Found a trick to let Gingerbread use the native SIP client without wifi restrictions, involved messing with a system APK. Long/short, damn near drove myself crazy trying to sign the APK until voila, came across a thread for Signapktic by XDA’s Fnorder and Stericson.
Signapktic signs APKs on your phone. Tell it where the file is, what key to use and where to write the output. Done.
One feature I wish it had would be figuring out a way to tell me five hours ago that it existed. But maybe one of you Android users out there could find this useful so if that’s you, get Signapktic, right on the market (needs root), use it and if you end up using it regularly consider throwing these guys a few dollars. Here’s your market link my man.