I am also curious about peoples' VOIP experiences. I'm getting sick of paying $25/mo for a voice line I barely use. I'd rather leverage the $65/mo cable modem I have (can't give it up -- too addicted to the speed!).
In particular, have any of you used SunRocket? Their costs and "no surprises" pricing seem unbeatable, although I have read absolute horror stories about their tech support.
After a week (and six hour on hold or talking to the wrong tech support zombies), I now have VOIP service. It works great, sound quality is as good as Verizon or SBC have provided to me in the past, and is under $17/month with tax.
I use SunRocket and have been really happy with their service. I've been using them for over a year now and have saved a considerable chuck of money. I'd be happy to answer any questions you may have.