Heh, like the use of black-and-white backgrounds. It's unique in that I haven't seen any other animator do that, and it emphasizes the characters, something that might not be as easy with a cluttered background.
The animation itself? Very smooth. Sometimes it's a little jittery, but only a little. If you want to improve your animation, I recommend flipping through the pages and drawings shown in "The Animator's Survival Kit." The actual inbetweening seemed like you inbetweened exactly in the middle. A big principle of animation is squash and stretch, and easing.
The actual characters were nice, and cleaner than a lot of the animations here. The voices were decent, as well.
It's a bit short, but it was a decent attempt at humor. I didn't find the actual joke very funny, though I'm sure it'd probably appeal to many other people and it just isn't for me.