Or a swift kick to the face if you can't access your hammerspace.
But yeah. I'm kind of a creeper magnet (not saying that everyone I know and talk to is a creeper, but I tend to get a lot of clingy ones).
My usual policy is to be polite, but distant. I continue with this policy sometimes for a very long time. If they want to hang out with me, I decline politely with a legitimate excuse.
With this, I am not rejecting them, and they can still talk to me and do whatever. However, they do not have access to me. In other words, even if they want to get close, I keep them forcibly at arms length and on formal terms. Eventually, they calm down and take on a more tolerable attitude. Usually, they even leave me completely alone after a while.
Right now, I'm currently exercising this tactic on a rather persistent and slightly socially inept ENTP, and, although it's taking longer than normal, it's working. It's not that I DISLIKE him, or any of these people really; it's just that I don't want to deal with emotional clinginess or awkward social situations with awkwardly social people. I really don't need someone else adding to my issues. I can make plenty of those for myself, kthx.