NetSling is a no-frills extension for Firefox that works with del.icio.us to give you quick keyboard access to google searches and any of your online bookmarks, from anywhere.
Here's how it works: Anytime you're browsing the web, you can hit CTRL-SPACE to bring up a prompt where you can enter a google search or a NetSling command. You can type simple words for your online bookmarks (like 'mail' to jump to GMail), or you can set up active bookmarks to run searches on websites you use often (like 'imdb John Cusack').
Once you start using NetSling, you'll wonder how you managed without it!
Want to know more? Download the latest release (drag the file to an open FireFox window), then check out the HelpPage.