I hope this can help out hobbyist and providers alike and save you some money.
Google voice is now available to the general public. What is so great about this is that you can essentially add another line to a cell phone, like the iPhone. You get a unique phone number that you choose, can make and recieve calls with this number, an if you miss a call, the voicemail is transcribed for you. I just signed up last night, but thought my friends here could utilize this tool.
Here's the link:
http://www.google.com/googlevoice/about.html
BTW, I don't work for Google.
Anyone wishing to pass on their savings to me is appreciated. Rest assured it will all stay in the family and be used for hobbying.