If your /home is on a different partition, say /dev/hda10, you can add that entry in /etc/fstab of your new distro.
/dev/hda11 /home reiserfs defaults 1 2
You would need to maintain the uid and gid of the users to match those of the original distro.
Some distros may have different starting UIDs. e.g. RedHat/Fedora start with 500, Slackware starts with 1000. You can modify these parameters in /etc/login.defs.
I am sure you must be aware that you can share the swap space too.