I haven't heard that, do you mean overwriting the previous? Or setting multiple boot with NTLDR.EXE?
Using windows you have to install the latest version first: 95, 98, Me, XP, Vista in order to get them to work properly. Is that the same with linux?
As I mentioned before, LILO is obsolete now. If you have more than one gig in RAM you don't need any swap. If you don't, you can create just one swap and all distros will use it.
Do they all use Lilo and do they all need swap drives, or can i create a dynamic swap drive that they all connect to, since they will be on the same drive