Facebook applications are the Java applets of 2007.
Either you'll know exactly what I'm talking about when I say that, or you won't. If you don't, you likely don't care anyway.
They're little, obnoxious ways of expressing your individuality by doing things exactly like everyone else. Top Friends is the new Java Applet that Simulates Ripples of Water under a Reflected Image. The different enhanced-poke applications are the new Java Applet that Just Renders a Button with Text on a Gradient Background that Changes Color When You Hover. Sure, some of them are a little Web 2.0ish, but most are pretty worthless and just clutter things up.
How long until hit counters and web rings?
I should make an application called Web 1.0 Nostalgia that lets you include gradient button and water ripple Java applets, and maybe that animated GIF of the "under construction" guy hammering at the ground with his shovel.