You can also just make a bootable disk (CD or DVD) and run it off that.
It will be much slower on a USB drive or disk than an installed on HD version. But it lets you see if your hardware is compatible.
People trying this should also note that USB drives can vary greatly in speed.
http://www.tomshardware.com/reviews/usb-3.0-thumb-drive-review,3477.html
How is a flash drive with no moving parts slower than a HDD that is spinning with a head that has to physically move across the sectors to read the data?
Bkmk for a future try at Linux...
As long as people realize the speed issue is due to the medium they are using, it should be a decent evaluation experience.