I noticed a few new extensions that I hadn't tried out over at Ed Bott's blog . PDF Download is one that lets you see how big a pdf file is when you click on the link and offers options of how you want to open it (tab,as html, or dowload). That's handy - nothing worse than clicking on some monster pdf file and waiting forever (fellow dialup users will understand).
Copy URL+ is the other extension which is an ideal tool for blogging or sending snippets from a page via email - will capture the snippet as well as the Title of the Page and the URL. Saves a lot of steps - definitely one to download.