Flipper,

Where are you? In the states you can get these (below) .. they work great using one output pin but they do not latch. I used them in testing equipment years ago and they were perfect. No zener needed, just a flyback diode across the coil. I drove mine direct from a PIC output at 5 volts since the coil resistance is 250 ohm.

http://www.radioshack.com/sm-compact...i-2062478.html