Another option (totally unhip or hip as heck, i am confused and don't know anymore) are the very comfy Teva-like Clipless Shimano Sandals that Sheldon 'Bike God' Brown wears 24/7 during summer months (check his site). He is a comfort kindoff guy as well a serious cyclist so it might be a good compromise if your location isn't too cold or wet. I think they are pretty cheap too...