Hum. I'm really itching to start an actual game project for a change, I've been coding only the engine for too long... I have a couple of choices in mind:

3D remake of an ancient game I made about 10 years ago
This was actually the first "finished" game I wrote, although the last version was 0.41 or something like that (I abandoned the project because of my lack of skills at the time colliding with feature creep). This would require me to implement terrain rendering in Spineless, but the terrain probably wouldn't be large enough to require any LOD algorithms, so a simple heightmap would do at least for starters.

A more recent, abandoned project
Spineless was still too instable at the time, and the artist got too busy with his work on a commercial title that he couldn't continue. Damn commercial games. ;) This one might be a bit too ambituous at the moment.

An old idea that's been circling around in my head for ages
This is actually more or less my dream game, but it's definitely too ambituous at the moment. I'm convinced I will write it some day though...

Yes, I was cryptic on purpose. I want to have something to show first before throwing wild plans all over the Interweb. I will probably start with the first option and post screenshots as soon as I have a basic terrain renderer working. I'm still not sure how much time I should give Spineless (it badly needs more tests and documentation), and how much the game. On the other hand, a real world game would be an excellent test for the engine, albeit not very formal.

I will continue talking about Spineless scene management tomorrow.