should be a featured extension Rated 5 out of 5 stars
difficulty: I have two extensions that are essential for me, both use the sidebar and are not very compatible with each other.
solution: have them on separate profiles, with the profileSwitcher extension.
If you extend, customize or config Firefox heavily... this extension is a must. You can have multiple profiles that act as specialized Firefox browsers, without them being one browser, bloated with too many add-ons.
ProfileSwitcher lets you switch profiles at anytime, select which profile you want at start up, delete profiles or add new ones at anytime.
cons: all profiles still share the same plugins. You can have them turned on or off separately per profile
I have used it on Ubuntu Linux and windows, Firefox 12, 13 Beta, and 13. and I have no problems... works perfectly.