I picked up a pair of the least expensive removable pedal at eurobike a few days ago, the design is nice because they use a hex styled axle that goes into the quick release connector which is screwed into the crank arm. So you can get the crank bolt out using a 6mm hex key, which could be nice for the folding world where you need to disassemble with minimal tools.

I'm going to try out a "poor mans" powergrip (I must have 4 pairs already on various bikes) with just routing some webbing through the pedal, as the other products seem to have done above. For bikes that aren't ridden much, this might be good enough.