Mozilla MiniT (drag indicator) Adds tab dragging with drop place indicator. Cool now you can rearrange the tabs.

Search Keys extension for Firefox
Search Keys lets you go to search results by pressing the number of the search result instead of clicking. For example, pressing 1 takes you to the first result. Hold Alt (Windows/Mac) or Ctrl (Linux) to open results in new tabs, or Shift to open results in new windows.
Search Keys supports [...]

Zipped version of Firefox 1.0 can be found here . When I started using Firefox (then firebird), one of my top criterion was zipped version, So can carry around firefox in a usb flash drive. But now there is a whole new project dedicated to this concept Portable Firefox 1.0 (USB Drive-Friendly)
Portable Firefox is [...]

[Update]
Google-Firefox

Atlast Firefox 1.0. I’ve have been using Firefox ( then Firebird ) for more than a year now. Sure firefox redefined my browsing experience.

A step-by-step introduction to Mozilla Firefox
Why switch to Mozilla Firefox?
Questions about switching to Firefox
Firefox realted links - Just Another Wiki - Mozilla Firefox

ScrapBook is a Mozilla/Firefox extension, which helps you to save Web pages and easily manage collections. Major features are,

Save Web page
Save snippet of Web page
Save Web page including linked files
Organize the collection in the same way as Bookmarks tree
Full text search of the collection

Works with Firefox 1.0 RC1 (for Debian)