How do I synchronize Firefox extensions?

"There are couple of ways.

Use the FEBE and CLEO addons to create a packaged XPI file that can be installed on one shot
The FEBE addon in itself is quite cool
but the CLEO addon helps package its files together into a single installable 'addon'
Create your Firefox Collections page to download and install whenever required
The Addon Collector would also be useful

Depending on your exact needs, either of the above two schemes will work.

Note that the FEBE sequence can actually backup a lot more than just your extension list.
It will also save your preferences and if you choose, your passwords, cookies, bookmarks, etc.
The FEBE method is therefore an excellent way to replicate your firefox installation on another machine
(or even another login on the same machine).

The Collections method meanwhile is very good to refer your extension list to someone else, or
get your favorite addons on a different machine where you cannot (or do not want to) access your FEBE backup."

"To synchronize your extension, you just synchronize your firefox profile.
Use dropbox to synchronize you Firefox profile folder.

Typically I don't synchronize my extensions, this is how I maintain my data consistent
across all computers

On Current System
1. Bookmark all my extensions on Delicious
2. I use Foxmarks (now XMarks) to synchronize passwords and bookmarks

Goto second system

Install Firefox
Install all the bookmarked extensionsr
Install XMarks and synchronize your passwords and bookmaks

This way I keep my data consistent across systems, and I still keep
each installation clean (by not copying extensions and profile)

Alternative to Xmarks you may also use Mozilla Weave.

Links:

xmarks.com

mozillalabs.com/weave/"