Alt+Tab limited to the current workspace
Update:QuinnStorm has patched this so it now applies against CVS and can be found in her latest debs or source tree, downloadable here
Update: Emanuel has just emailed to say this pacth doesn't apply against the latest CVS, and that it also has not yet made its way into CVS. I'll update you if anything changes, for now you can check the CVS changelog and get the latest code if things change (see the links to the side)
The Gentoo XGL Wiki has some information on patches to limit ALT+TAB switching to the current desktop only:
I looked at the latest CVS and it doesn't seem to be there yet... so just a patch for now - Please correct me if I'm wrong!