If you liked Google Toolbar 5 for Internet Explorer, but you didn't want to use Microsoft's browser, there's now a version for Firefox that includes similar features: support for Google gadgets, integration with Google Notebook, multiple profiles for AutoFill and synchronized settings.
The Firefox version doesn't include all the features that are available in Google Toolbar 5 for IE: there's no find bar, pop-up blocker, Browse by Name because Firefox already has these features. Customizable layouts, highlighting search terms, Word Find and Google Docs integration are the four Firefox-only features.
If you use Google Toolbar on multiple computers, enable synchronization to save AutoFill profiles, custom button and other settings to a Google account. Since bookmarks and notes are saved to the same Google account, you'll see the same Google Toolbar anywhere you go.
Google Toolbar 5 for Firefox - http://www.google.com/tools/firefox/toolbar/FT5/