I made a push button start and drew up the diagram for it. I picked up the stuff at the junk yard and after playing around with the ignition switch, I figured it wouldn't be too hard to simulate with relays.

Items required (almost all sourced from junk yard):
2x 4 pin relays and wiring clips
1x 5 pin relay and plug
Stock 5P ignition connector (brown plug)
Stock 7P ignition connector (brown plug)
2 switches
1 push/momentary switch

The pdf file is a sketched wiring diagram with all the data needed to do this.

In order to have a true push start, you will also have to disable the steering wheel lock as well.

 

this is good idea...it would be better if u could do it with some kind of wireless key like the new cars too