Before I went to WDW, I dispised Crocs, however after the wettest day I've ever seen ANYWHERE! (26th August 2007) I bought a pair of Crocs, and now love them, especially mine, as mine have mickey heads. The only downside to crocs, if you go to IoA and plan to do DD, you have to hold them or as we did, sit on them (I thought I'd lost one when I sat on them)
Oh and yes, there is a Croc shop in MCO, its quite good too, the walls are basically covered in crocs in all sizes, styles and colours.