Google Voice (Google Voice), which the search giant introduced in 2009, recently became freely available to everyone in the United States. Even though the service hasn’t dramatically changed since then, it’s still very useful to those that run small businesses, because it can give them an extra edge and make professional life much easier — at least, it can if you know how to use it.

When you register you can choose a virtual phone number in any area code. You can use that number to send and receive text messages, record voicemails and even receive and make calls over the Internet (Internet), but it becomes particularly useful when you attach it to the number associated with your mobile or landline phone.

There are some features we’d like to see added, but the current suite is still impressive. Google Voice can forward calls directed at your virtual line to your physical line, record voicemails and calls at both numbers, transcribe voicemails, share those voicemails with other contacts, block callers, apply special rules for individual callers or groups of callers, receive e-mail notifications of calls and text messages, and make unlimited free domestic calls and very cheap international calls. It even enables you to listen in on voicemails as they’re being recorded, giving you the option to pick up if you want to talk to the person who’s leaving the voicemail.

Here are our picks for five ways you can use all these features to make your small business more efficient. Add your tips in the comments below.

1. Search and Prioritize Your Calls

Most of Google Voice’s features fall into this category, but be aware that you have to actually provide contacts with your Google Voice phone number to use them. You can’t use many of the features we’re listing for calls received at your old number. This is a huge problem for small business owners who have already amassed an extensive list of contacts using their old number(s), but if you’re planning on switching pace and only handing out your Google Voice number, you’re all set.

Google (Google) will record voicemails on your behalf, then e-mail or text message you digitally made transcripts of every voicemail you receive. The robot transcripts aren’t perfect, but they’re usually clear enough that you can tell who is calling and what he or she is calling about. More importantly, they’re searchable.

Just like you can search your Gmail (Gmail) inbox or the web using Google, you can search the transcribed text of your voicemails. Voicemails have never been searchable before. If your business gets a high volume of calls, this is a killer feature because it allows you to avoid losing important calls.

Since voicemails and text messages are all up on the web for you to search and sort, you can process a lot of calls more efficiently than you would be able to with a regular, call-in voicemail system.

2. Use Different Rules and Greetings for Different Contacts

You can assign contacts to user-defined groups when you dig into Google Voice’s settings menu, then adjust behavior for those groups. You can say that certain individuals or groups should be connected to certain numbers when they call, or block some people from contacting you at all should you become harassed by unnecessary calls.

For example, you can determine which contacts will be calling to discuss business development deals and which contacts will be calling for product support, and forward those calls to the appropriate team member inboxes automatically.

You can also create custom voicemail messages for important clients or to represent certain divisions of your business. For example, the voicemail messages for your customer support and sales divisions could greet callers in different ways and with more relevant information on who to contact.

3. Share Calls with Your Assistant or Partner

Because calls, text messages and voicemails are sent to you via e-mail, you can easily forward them to other people working at your business. But that’s not all you can do. You can actually embed the audio recordings of voicemails and share them via e-mail or other communications media with anyone you want.

Furthermore, you can press a button while on a call to begin recording that call. The recorded audio will appear on the web, and it will be shareable as well. This can be very helpful for collaboration, or for looping a partner in on an important conference call that he or she couldn’t attend.

As we mentioned in the previous point, you can configure calls from certain contacts to go to specific team members, but you can easily transfer a call to a different number once you’ve received it, too. This is of course standard for normal office phone systems, but many of today’s small businesses are operated via mobile phones on the go. This is a welcome feature for business owners in that situation.
 

4. Set Up Shop Anywhere, or Nowhere At All

Google Voice allows you to pick virtually any U.S. area code, and that can be a boon for small businesses in a big world. Do you have a large concentration of clients in Chicago, but you’re based in San Francisco? Set up a Google Voice number in the 773 or 312 area codes so they have a local number to call for support.

From your perspective, the area code is completely irrelevant because all your domestic calls through Google Voice are free, but that might not be the case for clients, customers and other important contacts.

Let’s say you run a consulting business for Hollywood screenwriters, but you’re actually working from Dallas. Some of your potential clients won’t take you seriously if they feel you’re not connected to the City of Angels, so set up a number in area code 323 — downtown Los Angeles.

You can also use Google Voice to make dirt-cheap international calls. That can save you a sizable sum in this age of Internet business and e-commerce, when national borders have little bearing on who you might do business with.
 

5. Specify When and Where You Want to Receive Calls

You can tell Google Voice which times of day you’ll be at which numbers, or recover your sanity by saying you don’t want the phone to ring at all outside of business hours. You can also change these rules for specific contacts or groups, as described above.

Let’s say you’re about to go on vacation; you’re leaving the office at 1:00 p.m., then you’ll be in transit until 7:00 p.m. After 7:00, you want to clock out. Just tell Google Voice to connect calls received before 1:00 p.m. to your office landline, to connect calls received between 1:00 and 7:00 p.m. to your mobile phone and to block all calls after 7:00 p.m.

And of course, you can make exceptions for important contacts, such as your business partner, who’s holding the fort while you’re gone and who knows what news is important enough to merit an interruption. Specify that his or her number can reach you on your mobile at any time and you’re all set.

Auction Site eBay just announced that it has acquired  RedLaser, a nifty barcode-scanning application for iPhone, and related technology from Occipital. Terms for the deal were not disclosed.

The application has seen over two million downloads from the App Store and is one of the most popular barcode-scanning applications for comparison shopping. RedLaser’s barcode-scanning application, which looks up price comparisons in its product database, was created specifically to deal with non-autofocus cameras (i.e. mobile phones) and has licensed its technology to over 70 companies (though it’s unclear what the future of these agreements will be with the acquisition).

Unsurprisingly, eBay says that it plans to integrate RedLaser’s barcode-scanning technology into its iPhone applications, including its eBay Marketplace, eBay Selling, StubHub and Shopping.com applications. eBay has also made RedLaser a free app (it was originally $1.99) and will be integrating more than 200 million listings from eBay, as well as product inventory from over 7,000 merchants on Shopping.com.