Do you hate how, when you have a bunch of tabs open in Firefox, they scroll off the tab bar with right and left arrows?
To fix this, in the address bar type in 'about:config' without the quotes and hit enter. Scroll down until you see 'browser.tabs.tabMinWidth'. Double-click the number to the right of this, put in 0, and click OK.
When you restart your browser, it will no longer do that.