I love Greasemonkey. Here's what I use it for - a web site that I work with has a real problem with spammers "scraping" (ie stealing) it's content, displaying it on blogger blogs, and slapping ads up to make money. Invariably, these scrapers will hide the "flag this blog" tab on the Blogger template, making it very hard to bring the spam site to Blogger's attention. I little Greasemonkey script exists that unhides this flag button, making it easy to flag the splog for deletion.
