There is this incredible tool called smart boot manager. It can help you a big deal.
But apparently there was some mess in their sourceforge page. When you hit this url, it shows the dir content, instead of the page. Its no problem. Enter the lastest release dir and download the package. Will work ok. Or, better, read the about.html.
With smart boot manager you can install as many systems you want and have sbmr load them. Do this if you dont want to mess with grub-lilo thing.
You can share swap with these distros. Just partition for the new system, install it, tell it to use the already set swap and use smbr to load it.
Notice that nothing that I said replaces the link by penguin!