I've been wanting to check out Google Voice for a long time, and I finally got an invitation from Google to sign up. It is fantastic and I'm very excited about it.
You can use Google Voice either with your existing phone number, or you can get a phone number from Google. I chose one that is local to where I'm moving to. You can search for phone numbers that spell things, and I tried my first and last name with no success, but eventually got a phone number that ends in MATH, which is pretty cool.
What GV does at this point is that, when someone calls my new number, GV will ring whatever phones I've told it to. I can tell it to ring my office phone, home phone, and cell phone all at the same time from that one number that belongs to none of the phones. I can also, if I choose, set up classes of my contacts and have GV treat them differently. (For instance, perhaps business associates get to ring only my office and cell phones, but family get to ring all three phones.)
GV also catches all of my voice mails and will email me when I get a voice mail or a text message. Voice mails are automatically transcribed (not very well, but better than nothing) and there will also be a link to play the voice mail recording on the computer. Text messages come as they are, of course, but best of all, I can text the person back just by replying to the email. (I don't do a lot of texting, but now it is at least easy to do with those few people I know who do text me.)
I can place phone calls from my Google number from any of my phones (though I forget how) and I can also place them using the website as a helper. I tell Google who I want to call and from what phone, and they ring first my phone, and then the other phone, and make the connection. It's sort of like having a secretary. One of the advantages is that I can manage all of my contacts in Google (same contacts as in Gmail) and not in my cell phone. (Of course, I might also want them in cell phone if I want to place calls when I don't have access to a computer, but there are not that many people I call regularly from outside of my home or office.)
My favorite aspect is the voice mail capture and emailing. I am pretty bad at ever getting phone calls and I especially don't notice voice mails (much less texts), but I check email all the time. This will make my chances of receiving and returning phone calls much higher.
I also really like the idea of having one phone number that will stay the same no matter what kind of phone I have. I'm considering, once I move, having a prepaid phone plan so that I don't have to pay $40/month for the five or six phone calls I make every month. I know that you can keep your numbers when you change plans these days, but this seems so much easier - just give everyone the Google number and only you and Google have to know where it's ringing. (For that matter, if I wanted to make even fewer phone calls than now, I could just have the Google number and no actual phone plan, then find a phone booth or something to place calls when necessary.)
Anyway, I'm a big fan of Google Voice so far. I have one invitation left that I can send someone, so if you're interested in trying this, just let me know.