Laura R // I'm Laura, and this is my blog. I am a film & theater teacher. I also make films. I hope you enjoy them. My company: http://olivestreetfilms.com
I bought a Google Voice number on eBay, and I'm not ashamed to admit it. I paid less than $100 for the area code I wanted (after some minor haggling; some area codes had an asking price of over a thousand), and so far it's been totally worth it. The ability to track, screen, and best of all, block calls for free (ok, minus what I paid up front) is priceless.
The other huge feature is voicemail transcription. Without getting into a huge rant here about how much I loathe voicemail--a simple web search can lead you to several blog posts and articles with similar sentiments--one of my peeves is the fact that voicemail requires you to have to stop what you're doing, log in (usually), listen to the message (sometimes several times, if the sound quality is poor or the speaker mumbles), and occasionally have to replay it to write down some other info. Voicemail transcription, when it's accurate, saves you all of that agony. Google voice transcription is by no means flawless, but does improve with use.
I should note that, prior to my GV bid, I had been using PhoneTag, a vm transcription service that offers a free trial week and reasonable monthly or per-use fees. PhoneTag's transcription, by the way, is excellent, and worth it if you're mainly interested in this feature alone and can wait for the Google Voice beta to go public...
...which, so I hear, will be "soon".
Sent on the go from my Peek