If you have a mobile that you can use in Europe and easily can use as a WiFI accesspoint I would buy a Kontantkort (SIM card) from 3 that mostly have the best speed.
You can buy it from many petrol stations and bigger supermarkets.

If you don't have nessesary hardware just go to one of the phone shops in the town.
Phonehouse, Telia, 3

Here is e.g. the offer from 3
http://translate.google.com/translate?sl=sv&tl=en&js=n&prev=_t&hl=sv&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.tre.se%2FPrivat%2FMobilt-bredband%2FDataPrepaidPage%2F

If you mainly will stay at one place during your visit and it's in the middle of nowhere, check with any locals before just to be sure the operator have a good cover.