Washing laundry on longer camping trips?

[Preston Graham]

We have a nearly 4 week camping trip coming up this summer and I seriously can't wait! My wife just bought something to my attention and I can't believe I overlooked. How are we going to wash our dirty clothes?

Um, no idea! Can you help me out with some suggestions on this. The plan is to only go into town for quick food runs. Where we are going, I think that is about all there is.

Ideas would be appreciated!