A former ATM skimmer maker, now “reforming” has a nice idea to slow down skimmers on ATMs, basically you would put the card in long ways, a motor inside would spin the card sideways (inside it) and insert the card. This is a good idea and will slowdown skimmers, but I have a feeling (and some ideas) how to get around this. Just will cost more in hardware.
http://www.theregister.co.uk/2013/05/17/romanian_hacker_atm_security/