I love shit like this and a lot of my friends do, as well. This site is a useful reference but I'd be remiss if I didn't mention my two favorite grammar books: Lynne Truss' Eats, Shoots and Leaves and Karen Elizabeth Gordon's The Deluxe Transitive Vampire: A Handbook of Grammar for the Innocent, the Eager and the Doomed. Both are superb and handle their subjects with plenty of wit.