WARNING: It appears that these directions don't work for the Kubuntu. It isn't clear why, but the kernel module doesn't seem to load properly. This may require the compilation of a custom kernel. If you figure it out, please post below how you did it.
I found the information on the forums a bit scattered and/or outdated so I was encouraged to write up a quick post to inform others who might be searching for the same information I was how to do so quickly.
If you would like to get TrueCrypt install on Gutsy, the good folks over at the TrueCrypt website have made it pretty easy. If it was in the repositories it would be even easier, but this is about as close as it gets. No totally anonymous packages or fresh compiles against kernel source...
Simply visit http://www.truecrypt.org/downloads.php and select the appropriate 7.10 package from the dropdown box and run it. It will open in a package manager you may or may not be familiar with. In this it is as simple as clicking Install and following the directions. You'll probably have to put you password in, then it may need to install some dependencies, but the beauty of apt is that it will handle that for you.