All of the major tabbed browser (Firefox, IE7, and Safari) have a nice feature that allows you to quickly close excess browser tabs. If you have a lot of extra browser tabs open that you want to close, go to the tab bar and right-click on it. This will pop up a menu with an option to "Close Other Tabs", clicking it will close all of the other tabs open in your browser leaving you with just the tab that you are currently looking at. So far as I cn tell, Firefox and Safari have no keyboard shortcut for this command (which is unfortunate), but in IE7 you can press Control + Alt + F4 to execute this command from the keyboard.