If you don't walk in your cycling shoes, try some road pedals, like Look or Time. They are SOLID-once that big cleat is in there it is not coming out unless you want it to. No way I could pull out of my time pedals by accident. You could flip my bike upside down and shake it and I'd still be clipped in. As a bonus I find skipping and skidding is way easier with them than my SPDs. Still, for most of my city riding I just go with the shimanos for the walking convienience-you really can't walk in road shoes and cleats.

As for the egg beaters, they do resist pull out better than SPD style. When you pull up, the mechanism tightens on the cleat. I only had mine for a couple of weeks, and they bugged my knees, so I can't comment on long term reliability.