I had researched this too last year, esp for running in the colder weather with slush outside. I read about runners using duct tape across the toe of the shoe to keep the wet out and for keeping cold air out from toes in winter months. I did this and had great success in keeping my toes warmer and the wet out. (My toes get cold quickly in general and I had just started running and didn't want anything to be an "excuse" to not run in the cold so I was looking for solutions and it worked!) You might get a little tape residue on your shoes when you take the tape off but hey--they're for running and getting pounded on and in!--not for a runway fashion show!

I hadn't even thought about this aspect. I've noticed that there are cooling slots on the sides of my shoes and this would mean water could come in the same way. Me thinks duct tape is the solution once the weather gets wetter and colder.