I used the Drymax Trail Running Socks at Javelina. These socks do not contain any vents, the absence of which helps to prevent dirt from getting in. They are also have a double welted leg with extra padding around the ankle, protecting the leg and sealing the top of the shoe to keep out dirt and debris. They have a great fit and are seamless.
Another added bonus for me with Drymax Socks has been the lack of a need to tape my feet prior to an event. In the past I have spent over an hour the night before a race taping. Now, I can use that time to relax and get some additional snooze time.