'Jotun' in old norse just means 'huge'. And the mythological ones were generally much larger than the Ęsir (gods), although they came in many sizes and shapes.
If the url works, it has a nice pic of a norwegian troll - as you can see its very much an 'elemental force' and nothing like a 'mainstream fantasy troll'
http://www2.norwayshop.com/cgi-bin/o...p/sh.pl?500642