I was wondering if it is possible to dual boot 2 (or more) Linux operating systems. I have googled all over the place, and I could only find info on dual booting Linux/Windows.

I have SuSE 9.2 installed and wanted to install Fedora C3 just to check it out. During install I ran into errors saying that Fedora needed the '"/ drive". I tried giving FC3 the "/drive", but I recieved warning errors about erasing the data (SuSE) on the drive.

So, the only other thing I could think of would be to make an empty partition before install? If so, what tool do I use to do that?

Yes, you can dual boot linux OS's. You just make a spare partition for it and install to there. You can share the swap. When installing the new linux, have it install lilo to it's boot partition, not the mbr, then set the lilo/grub in your original linux to boot the other lilo/grub...

That's the easiest way, tho there are ways to avoid having to go through two lilo bootloaders if you want to. That usually involves copying kernels around and stuff

There is a multiple distros howto on distrowatch: http://distrowatch.com/weekly.php?issue=20040614#2