Toolbar

Display all Google services as buttons or as a space-saving dropdown menu next to your address bar. Reach services like Gmail, Google reader, Google maps, Google calendar, and many more in a single click from your browser.

RetweetFollow lets you search by keywords in URLs tweeted and to easily follow the retweeters. You can also create lists, export the results, thank the RTs.

If you use bi.gl frequently, you can bookmark this link (usually drag and drop to the bookmarks toolbar): Short url with bi.gl. When you click this bookmark a short URL for the site you are currently visiting is created, without you having to visit bi.gl.

TracerLock is your complete web monitoring/web clipping service.

Think beyond bookmarks. Inslices helps you to collect, share and organize relevant web pages selections while surfing.
Collect articles, videos, products, and other pages selections, or let Inslices suggest them for you.
Easily share and interact on your findings.
Keep track of your slices and follow other users discoveries.

Like-o-matic is a bookmarklet designed to let you Facebook "Like" quite literally any website you’re currently looking at. No longer will being tricked into liking a different page than you’re presently on be a concern.

In the age of sharing, linking, retweeting, capped attention spans and character limits, people need things to be shorter, better, faster, stronger. The Ow.ly social bar is your answer.

Quix is an extensible bookmarklet, that allows you to easily access all your bookmarks and bookmarklets, across all your browsers, while maintaining them in only one spot. All you have to do is remember the shortcut for the bookmarklet, so, basically, it’s like a command line for your browser.

The Digg Toolbar for Firefox lets you Digg, submit content, and keep track of Digg even when you're not on the Digg site itself. With a notification window built into the toolbar, you'll never miss a popular story or when friends Digg, submit, or comment on stories.