business phone services
Google Voice
Google voice is currently by invitation only. Check it out.
Grasshopper
It claims to be The Virtual Phone System Designed for Entrepreneurs
Features include:
Phonebooth
Phonebooth offers a free service and a $20/month service. Phonebooth Free is the cloud phone system that is perfect for small businesses, freelancers and independent professionals. And when you're all grown up, flip the switch to Phonebooth OnDemand, a full-featured office phone system with support for HD desk and conference phones.