I have been meaning for some time to post a couple of words very similar in Icelandic and Swedish and point out the differences. Some of these can be quite a bit confusing and we Icelandics tend to mix up sometimes.

Here is a short list, English translation follows in paranthesis.

hemsk (se, horrible) != heimskur (is, stupid)
rak (se, straight) != rakur (is, moist)
kåt(se, horny) != kátur (is, happy) - even though with one often follows the other ;)
hämta (se, fetch) != heimta (is, demand)
samt (se, and) != samt (is, anyway or still as in 'but still')
skyr (se, avoid) != skyr (is, milk product bit similar to yoghurt)
skata (se, magpie - a bird) != skata (is, skate - a fish) - how did you Swedes think of using the old norse word for this fish for a bird ??
gös (se, pike-perch) != gæs (is, goose) - has caused problems in restaurants :-þ
rum (se, room) != rúm (is, bed)
säng (se, bed) != sæng (is, cover)

Last I'd like to mention that the Icelandic female names Ragga and Kolla are not so good to have when in Sweden :)

The list is by no means complete, but that's all for now :)