Hi jasone,
you can use checkinstall for this. You find the package in the "extra" directory (
Link removed ). With checkinstall you are able to install programs and build a package on the fly. This means you are able to uninstall it after the installation with "removepkg name-of-the-package". You simply install checkinstall, do a "./configure && make" and then type "checkinstall". In case where the last step isn't "make install" you append the appropriate command, e. g. "checkinstall make all".
It works great, I use it for all my custom compiles.
Edit: I just noticed that the search with Slackware's package browser gives you no result. You can get checkinstall e. g. from here:
ftp://ftp.gwdg.de/pub/linux/slackwar.../checkinstall/
Of course you can get it from any other slackware mirror.