I use these nylon booties on tours. They are lightweight, fold pretty flat for carrying, and while they are not 100% waterproof, they do at least keep the wind off so my feet stay warm:
http://www.mec.ca/Products/product_d...=1107797957363

I use neoprene booties, something like these for colder days and they do a better job of keeping my feet dry. The down-side is that they are bulkier:
http://www.mec.ca/Products/product_d...=1107797957365

But the ones you suggest would probably do the trick too.