What I've done in the past when I have only one partition for my Linux insallation is to grab a bootable CD such as Knoppix or SuSE Live Demo. Once this is up, I delete everything but the home directory, then rename that directory to /home2 (Just to be sure). Durring the installation I opt to not format the drive. Once the system is installed I login as root and move the files from the /home2 directory, or just make the /home2 into the /home directory.
After the installation be sure to set the properties!! You would need to do this if you have a separate /home partition as well. Most distributions don't use the same UID / GID scheme so you will have to enter the /home directory and issue a command such as:
chown -R <username>:<groupname> <username>/
If this were my /home directory on SuSE 9.3 it would look like this:
chown -R rmasci:users /home/rmasci
Wait we're not done yet, you need to go into the /home/<username> directory and issue one more command. In each home directory there are hidden files and directories, these start with a period such as .kde. You'll need to issue the following command:
chown -R <username>:<groupname> .??*
You might ask, "Why not just do a .* instead of .??*" Well this is simple... if you issue a command 'cd ..' you will go back a directory, by issuing a .* the system would match '..' causing the command to go back into the home directory, and I've seen people change the entire home directory permissions with this command because they didn't include the question marks. The question mark represents a wild card for only one character, while the * represents a wild card for many characters. What we're saying with this command is to match every file that has a . with at least two characters after it. This way it doesn't match the .. FYI, most Linux installations the chown command is smart enough to stay within the directory if you did issue a .*, but if you were on a system like Solaris 8 it isn't so it's good practice to use the .??*.
Best of Luck -- Rich