but wisp is $250, thats a great deal of phone calls to only be able call someone else with an ip-phone.
I have been using Vonage ( www.vonage.com ) which uses a Cisco ATA186 to plug into the broadband connection then uses a regular phone. It works great.
They have just dropped thier pricing as well.

Of course, its about as much use as an IP phone if you don't live in the US