There's a new sync server software called Rainy, intended to substitute for U1 note sync, and it works nicely with both Tomboy and Tomdroid. Unfortunately it's not quite compatible with Conboy, which uses POST requests for OAuth unlike the other clients, as discussed here.

The Rainy developer doesn't have time to add POST support any time soon, so is there someone who could change Conboy instead? I looked at the source code, and looks like it would be relatively easy, but I'd prefer someone with better C skills to implement it.