On my computer, I have Ubuntu 11.1 and Kubuntu 11.1 installed as dual-boot. When I started, I specified completely separate partitions for both of them, but I now realize I want them to share the same home folder, i.e. the same desktop (I keep everything on my desktop). Any way to do that now, such as any software or any sort of reinstall? (P.S. - My Ubuntu partition is completely set up but I will be fine deleting and reinstalling Kubuntu).
Yes. As long as you created your user account(s) and group(s) in the same order, then Kubuntu and Ubuntu should have given you the same account and group ids. However, if you just wanted Kubuntu because it uses the KDE desktop, you could have installed that on Ubuntu after the basic installation, and select which desktop you prefer when you log in.