So I did a little minor research on this, and now do I not only wish I had it, but didn't print out so many business cards a few weeks ago.
Google Voice lets you have one Ph# in whatever area code you want that will simultaneously ring all your other phones so that no matter where you are, you don't have to miss a call, and no matter who is calling you, they only have to call one number.
It allows you to read your voicemails in text format, which could come in handy if you are in a noisy environment or don't have a phone nearby.
It also allows you to screen all your calls like an answering machine before answering, if you choose to answer.
But one of the major draws to this service, is the "FREE" minutes exploit.
(If you primarily use your cell hone for out-going calls, then this is what would interest you)
Some of the major cell phone services providers (Sprint, T-Mobile & Verizon) offer a Favorites plan, where you get to choose a certain amount of phone numbers that you can call, regardless of their service provider, and not be charged any minutes. A you choose your own "IN" plan. You set your Google Voice Ph# as your "IN" # and all you do is call that number before making any outgoing call. Now you have unlimited talk minutes for all outgoing calls as long as you remember to route it through GV.
That would especially come in handy for people that run their business on the go(like myself), and can't check every phone for missed calls every 30 minutes.
I could put 2 #''s on my business card. My GV # and my main office front desk #. My GV would then ring my home office, & cellphone with every call, so I would never have to worry about missing a call again.
I checked my gmail account and I didn't receive an invite, but I hear you had to sign up for it a while ago. Kashogi, whats up wit the invite? hook a brotha up.