Not many people know about the built in perl extensions to urxvt. There are a bunch of them, but the one I find most useful is tabbing. All you have to do is add:
to your ~/.Xdefaults file, and restart your terminal.You'll get something like this:
The keyboard shortcuts are what make this awesome. Shift-down to create a new tab (or click 'new'), and Shift-left/right to cycle between tabs.