It's a Crab Spider, one of the ground or bark variety, which have very poor eyesight, but are extremely effective ambush predators on anything that gets close to where they're hanging out. Like almost all spiders, they're quite harmless to us. I'm not familiar enough with Euro/Scando spiders to say which one it might be, but here's a link to a site run by a man who knows his stuff; you could ask him:

http://ednieuw.home.xs4all.nl/Spiders/sp...

Need to zoom in....can't tell

What spider is this? I saw it at work and i live in Iceland, never have I seen a spider like that. When i poked it with a pen it went to this defense mode, started retaliating. Any ideas? And it was quite small, alittle bigger than a thumbnail including legs