[malikor]

Originally Posted by PsychEroc

Extension List Dumper (also part of MR Tech Toolkit) lets you save a list of you add-ons, like this:

InfoLister does this as well. Can create a list of:
Extension List
Last Updated Time
User Agent
Themes List
Plugins List

and can export the data in any of these formats:
Plain Text
Simple HTML
BBCode
XPI List
XML
XML + XSLT
Custom Template