
You can use the profilemanager to load them specific profiles from the command line. It's very very slow to be running Firebug and have multiple tabs open.

So I have profiles with upwards of 40 Addons installed and enabled, and another profile that is built for speed. The solution to all these problems is to use separate Firefox profiles which use separate folders to store your profile-specific extensions and settings. Now I am trying to migrate them all over to Google's Gmarks, which knowing Google will be awesome eventually. So with over 5 thousand bookmarks I finally did some debugging and discovered that was a huge cause of Firefox acting slow. I have been using Firefox since it launched way back when, and I have always kept my bookmarks when moving to new machines and new installations. Also, bookmarks and settings like that have a performance hit. ( unless you are running your profile folder in TMPFS).

The more add-ons you have, disabled or not, the slower Firefox is. Lately I've been listening to Kings of Leon Radio. I like the idea of the last.fm but it's not as powerful as the site, which is awesome. Other than those, Firebug, YSlow, LastPass, and Web Developer are the only ones I always use regularly. The 4th button there is just a restart button. Very very helpful for me as a web designer. These buttons allow me to clear the DNS/Cookies/Cache for whichever site I'm on when I click it. As this screenshot shows, I only use a handful of add-ons at a time.
