I found out after I opened a Vonage account (of course) that if you pay with your Visa card you get a special offer (first mo free, no activation fee). Just go to Visa.com then click on shopping discounts or something like that and search for Vonage. The offer I saw was only good until 10/31 though.
That said, we are very pleased with them. We also have Roadrunner and have no trouble at all. I love the fact that it e-mails me when I have a new voice message as I sometimes forget to check the phone when I walk in the door.