Google releases so many products - most of them free - that it's easy to overlook one that's really special. Google Voice qualifies.
Thanks to its features and competitive potential, Google's relatively new service has been quietly sending tremors throughout the telephony industry.
And Google Voice - a service that's like a supercharged telephone number that you can use from your cell phone, smartphone, or from Gmail - is gaining traction, offering features that are either unavailable with other phone numbers or available only at a fee.
There is, though, a bit of bad news - at least for some. Currently, Google Voice is only available in the US.
However, the internet is full of workarounds for international users who sign up for the service via virtual private networks (VPN). And once a number is procured, the service can be used freely.
Moreover, Google plans to roll out Voice internationally. The only question is when.
But whether you get Google Voice now or in the near future, it's likely to make you rethink your current phone setup - or, at the least, to provide you with some attractive, free options for enhancing how you use your existing lines. So what can the telephony product do for you?Aggregate phone numbers
Anyone who juggles multiple phone lines and hates missing calls will love Google Voice. Once you have a Google Voice phone number, you can set it up so that any calls you receive on the service will automatically ring all of your other telephones, acting as a real-time call-forwarding system. If there's a telephone nearby, you'll get the call.
Google Voice takes voicemail to a new level, thanks to a number of features that will be a boon to those frequently playing voicemail phone-tag.
One feature allows you to set up personalised greetings for particular callers or particular types of callers.
So, for instance, you might want to set up a fairly formal greeting for business associates, while friends and family would hear a whimsical voicemail message, complete with music and sound effects.
Even more useful, however, is Google Voice's ability to transcribe voicemail messages into text. With this enabled, you could automatically receive an email transcription of a voicemail message while you're in a meeting.
You'll also have an instant record of all voicemail messages received - thanks to Google Voice's integration with Gmail - and you can easily forward a voicemail message by email as well.
The transcription capability in Google Voice is a transformative feature that might make you say goodbye to listening to voicemail messages the usual way, and it works surprisingly well.
For anyone who hates the peremptory nature of carry-everywhere cell phones and smartphones, Google's call-screening feature will be welcome. With it, you can preview who is calling and then determine whether to answer the phone or send the person directly to voicemail. The choice is one-touch simple.
Voice also makes it easier than traditional phone services to block particular callers. Can't seem to shake pesky calls from a business or acquaintance? Just select the record of the calls in Gmail, and follow the instructions for blocking unwanted calls.
Using Google Voice
Once you've set up a Google Voice number, there are multiple ways that you can use it. Firstly, it is available as an internet-based application, through your Gmail or iGoogle account, with a simple and clear interface.
In this sense it's very much a competitor of Skype, which up to now had pretty much locked up the internet telephony market.
Skype still has the edge over Google Voice in some ways. In particular, there's no video conferencing feature in Google, whereas in Skype, one-on-one video calls are easy and fun.
Google Voice's conferencing feature - which requires adding additional callers to your current call as the calls come - is arguably less friendly than Skype's as well.
But Google Voice's crowning achievement is that it can be used from most smartphones - removing you from the need to be at your computer to make or receive calls and potentially cutting down drastically on your cell phone bill.
BlackBerry, Android, and Nokia users can point their phone's browser to m.google.com/search to get the right version of Google Voice installed on their phone. iPhone users need to get Google Voice from iTunes.
Once installed on your smartphone, though, most of what makes Google Voice worth having is available at your fingertips, no matter where you are. That's why, once fully rolled out, Google Voice may just be the next must-have app for the masses.