If you live in Gmail anywhere near as much as I increasingly find myself there, these three new/updated Greasemonkey scripts (Saved Searches, Gmail Macros, and Conversation Previews) are truly magic. I am in awe, in particular, with the macros, which include the obligatory delete, as well as a really nifty label selector for jumping from folder to folder.
obAside: For those of you not familiar with Greasemonkey, it is a species of add-in for the Firefox browser that allows you customize the browser’s behavior on a site-by-site basis. For example, Gmail doesn’t include a straightforwardly accessible delete function, and Greasemonkey gives it back to you. Not to overdo it, but Greasemonkey is the main reason any rational and non-Microsoft-hating loon would use Firefox.