Go to the Mall of America. Seriously, you can easily burn that 3-4 hours there without spending a cent. (and I don't even like malls/shopping/etc!)
There are a few good breweries if you are into that sort of thing, I can get specifics if you are.
Haha, I think I'm going to end up going to Mall of America with friends, it's Friday when I'm going to be alone.
By St. Paul, I think you mean St. Paul Missery? How do you plan on getting there, car or plane? If the former, I think Wisconsin isn't too far out of your way.
I have no idea what "Missery" is. But to be specific, on Friday, I'm dropping people off at:
MYTH NIGHTCLUB ~ 3090 SOUTHLAWN DR, MAPLEWOOD, MN, 55109
And will have a couple hours to kill alone after that.
It's rather hard to go to Wisconsin when I'm with a couple friends. "I need to go meet a little boy who I met online" -- yeah right
However, if you can get to somewhere near Maplewood, which I hear is part of St Paul, then that's different.. I'm going to be alone in that area.