Five Finger Shoes

Okay I saw these and all I thought of was some X-Men character.  They are really weird looking but I would like to try one a pair.  I thought of going to the nearest store and just trying on a pair but I didn’t.  Where are you suppose to where these shoes at?  The beach? Hiking?  How good can they be?  Do they grip well or will you be slipping and sliding everywhere?  Does anyone own a pair of these Vibram Five Finger Shoes?