I just found these things:
Dimension Instep
Pedals with straps that clip into your clipless pedals so you can ride with "normal" shoes without swapping out pedals. I haven't tried then, but it's a great idea.
for Look:
http://www.performancebike.com/shop/...-_-null-_-null
for SPD:
http://www.performancebike.com/shop/...-_-null-_-null
Universal:
http://www.jensonusa.com/store/produ...r.aspx?sc=FRGL