Installing from source is probably the easiest way, Unless someone has already made a package available (though I haven't looked for one yet.)
Another option would be to build a binary package from source. that way the program will be logged in /var/log/packages/ and you'll be able to remove it very easily if you want.
Take a look at http://slackwiki.org/Writing_A_SlackBuild_Script
for a good How To for building a binary package.
/* Edit: You must have been installing while I was typing