The “iGoogle Search Toggle” GreaseMonkey script solves a problem that’s annoyed me for a long time.
Google’s custom home page feature, iGoogle, is great, except that the top 1/3rd of the page is occupied by a giant logo and search box. This is redundant with the search box that your browser already provides, and takes up a lot of screen real estate that is better spent showing you your actual content. So the above script simply hides that whole area of the page and replaces it with an unobtrusive little toggle button that will open it on the rare occasion you might need it. Click the thumbnail on the right for a screenshot of what it looks like.