Can you run games off External Hard drives ?

Hi i have been considering getting an external hard drive for my computer and i was wondering if you could run games off one. I have heard about fire wire but i dont have a port on my computer so will a USB 2.0 do ?

Here is the External Hard Drive I am conidering buying:

Buffalo 500GB Drive Station TurboUSB With Power Saving Mode USB External Hard DriveInterface Type: Hi-Speed USB

Data Transfer Rate: 480 Mbps

Spindle Speed: 7200 rpm

Storage Controller: Serial ATA ( Serial ATA-300 ) - Hi-Speed USB

I want to be able to run games such as Battlefield 2, Microsoft Flight Simulator 2004, Rollercoaster Tycoon 3 etc...

So Basically would games run that are installed on an External Hard Drive on my or someone elses Desktop on USB 2.0 Thanks