If you don't want to be reliant on (or still don't really like using) a trackpad, and tire of dragging a full-sized mouse around, then the Odin, a laser-projected mouse, might be worth a look. You've seen (even very recently) laser projected interfaces that cover keyboards, but the team that made Odin says it's the world's first laser-projected mouse interface. Which sounds pretty cool... as long as you're willing to carry around the disembodied head of a tiny Transformer when meddling with spreadsheets. We just gave it a cursory web browsing test, and while it lacks, obviously, the physical feedback of either mice or clickable trackpads, it behaves a whole lot the former. We just wished it looked a little, well, subtle.