Need to customize how many tabs you see in your Firefox window? Custom Tab Width is a really neat add-on for Firefox that makes doing this task really easy. It lets you customize the minimum and maximum tab width. Once installed, you simply need to go into the options for the add-on itself and then set the min number for the minimum size in pixels and the max number as the maximum number of pixels.
Thus far, after playing with the add-on in question, I think anywhere from 40 to 50 is a good minimum tab width. You could go all the way down to 1 though if you really wanted to (however, this pretty much makes the tab bar impossible to use). So why is this so exciting to the masses? Well, you used to be able to make this tweak in your about:config settings – however it appears that in Firefox 4 they took this feature out and moved it into the theme’s settings (to give more customization features to theme designers).
Want to pick up Custom Tab Width? You can do so by download it from the Firefox Add-ons website.