Sorry, I never tire of getting more cowbell. So here are 2 sites to have some fun with.
Walken Clips has a ton of sound bites from Christopher Walken movies. "Does your mother sew? Well, get 'er to sew dat!" (Joe Dirt). You can also view the "Weapon of Choice" video there.
Cowbell Soundboard will not only give you all the bites from that classic skit, you can play the BOC song and actually play cowbell along with it by continually clicking on the Will Ferrell/Gene in the bottom left corner.
I mean really... explore the space.