This weekend, I bought some Vonage hardware and set up an account with them. I'll be testing it for about a month, but if all goes well I'll be dropping the landline and moving the old number to the new setup. What'll be cool is paying $20+ less (after adding a fax line) per month, and getting more features in the process :-)
For those with my current number, it'll still work during the testing period as I've got call forwarding set up from the landline. It's my outgoing number that might be confusing (678 area code), but that'll only be for the next month or so.