I'm signed up for a gravel / paved road race with some double track tomorrow where my feet are likely to get wet in a creek crossing or two. It's been dry as a bone around here the last few months and I've not had to deal with this yet, however it's rained cats and dogs the last couple days and people who've pre-road the course say your feet will get wet. The forecast is for sun and a high of 40F.

Here's the equipment I have:
Non waterproof / summer mountain bike shoes
Thin, medium, and thick smart wool socks
Neoprene toe covers
Full Neoprene booties
Chemical toe warmers
Plastic baggies

What are your best ideas / experiences with keeping your feet warm and or dry. It's too late to get any more cycling specific equipment, so I'm stuck with what I've got and what's available at Wal-Mart. Thanks!