How can I keep my feet from falling asleep while riding?
I've been suffering from this recently now that I've upped my mileage to 40+ mile rides. My solution was 3 fold:

1) Starting the ride with my shoes quite loose. I have Shimano road / race shoes with 2 velcro straps and a ratchet strap across the top of my foot. I found that I was ratcheting the shoes down too tight.

2) Cleat position. Try experimenting with your cleats in different positions, I've found having my cleats at the rear most setting, allows some of the pressure to be taken off the balls of my feet.

3) Insoles - I've bought some decent insoles as I have quite a high instep, which means all the pressure gets put through the ball of my foot.