Yes, go to Radio shack, etc, and get a 7805 voltage regulator "chip". It has 3 pins. Across 2 pins will go your 7.2v and across 2 pins will come out 5V and they will share a common ground. Ideally you put capacitors on each side as a "shock absorber" when you plug it in (no pun intended), but some people don't. Voltage regulators get hot, and you should attach it to something metal to keep it cool, like an Altoids box, but make sure the electrical leads don't short out.
Find a spare USB cable with the appropriate end on it, cut it, and you will probably find red,black,green, and white wires. Red is +5V, Black is Ground, and these go to your voltage regulator, ignore green and white.
The most important thing is to check and double check everything with a voltmeter to make sure you don't have something backwards BEFORE you plug it into your MT. If you have something backwards, bad things might happen to your MT, so make sure everything is correct.