One of the things I missed most in Spaces is the ability to use F1, F2, ... to switch Spaces. One finger for me is much better than the two-finger options that are the only possibilities with Spaces.
I found a way around that by running You Control Desktops at the same time as Spaces. This is completely amazing, but both can run at the same time, and both seem to use similar mechanisms for switching. As a result, the keyboard shortcuts you set with You Control Desktops actually do work and will switch you between desktops.
Other little niceties: you get to pick other transitions; you get named desktops instead of just numbers ... all while having the nice Exposé-like feature designed by Apple. I am sure there must be some conflicts in some situations, but I have not run into any in the way I use virtual desktops.
[robg adds: I haven't tested this one.]

