Vonage Softphone

I asked this on the local Linux user's List, but thought it might be interesting here as well. I want to use kphone, kcall, or gnomemeeting or something like that on Vonage's softphone service. Is anyone doing that now? I know Vonage has the softphone, and you can use Xpro for Windows (that's what I think its called), but I want to use Linux. Any thoughts? -- See Ya' Howard Coles Jr. John 3:16!