Joe,

Check out the voicemail service from http://www.voicemailandfax.com - I've had a number with them for about 2 years at $9 a month and it's a slick service that lets me get voice mail or faxes from folks in my inbox (or notifications on my cell phone) then I can call people back on my own time.

I've also heard good things about http://www.kall8.com/ and you might want to check them out too.

Steve