Yeah, I've been. Pretty, very unique, small (population-wise, like 100,000 folks or so I think), very friendly people, expensive, great nightlife (surprisingly) and absolutely nothing to do once you’ve seen the sights (mainly the warm geothermal springs).
Icelandair usually has great deals from the east coast to Europe (through Reykjavik) so if I’d do it, I’d just stop over for a night or two, get a feel for the place and then move on (if you’re already going somewhere else that is).
Don’t get me wrong, it’s a nice place, but it’s just not the most exciting place imho.
(MrMuscle is from Norway)