I've always used this small script I made for creating pkgs, maybe it can be useful to someone

http://sites.google.com/site/gatewayasteroid/
(safeinstall)
I wrote it exactly for being "safe" (no root rights needed)JRD wrote:checkinstall already do the same.
But be carefull, it not always works and will not install the files in the right place most of the time.
the SLACKBUILD method is more "formal" and it's very good for making packages to be shared.