Things to try

I want to implement automatic mesh unwrapper (for normalmapping, lightmapping or similar). Not that I need it much, just so, for it's own purpose. The most recent thing I've read is Bounded Distortion Piecewise Mesh Parametrization; now I only need to find some time to actually do something. Ain't an easy task!

The other thing to try is: take ATI's NormalMapper and take a look at their octree implementation. Try replacing it with several regular grids, or tweak the octree. Fun project, also without any real purpose... (again, the reason I don't do this is "no time" :))

Finally, I have one really stupid&simple soft-shadows idea for oldskool projected shadows. It's something between Mitchell's 'Poisson Shadow Blur' and Valient & de Boer's 'Fractional Disk Soft Shadows' in ShaderX3. I think actually trying to implement it (instead of just an idea that came up while taking a bath) would be only several hours...

I must sound like a loser complaining about lack of time. The truth is, I could get that time probably, if I'd were more organized.