U cannot download a trial because Linux is free, there wudn't b a need for a trial version. If u get a Linux mag for a look shop or summit they usually come with a version that boots from cd, i.e. Knoppix.
Well, i thought so, thta it is free but i found a red hat linux installed on on of the pcs and i searched for it, i think it was a server, and it gave me prices and stuff.