Next time someone who uses TextMate starts blabbering on about how awesome snippits are, politely remind them that Vim supports snippits as well. You can download the snippitsEmu plugin here, and it works quite well. For those unfamilar with snippits, they allow tab-style completion of boilerplate code. For example, you might type class, hit tab, and then a template for a class will be expanded based on the current filetype Vim is set to.
Update: Several readers have cited snipMate as a preferred alternative to snippitsEmu. Thanks guys!