I've been playing around with a trial version the focus stacking program Zerene Stacker. I find it does a good job of increasing the DoF of macro shots, obviously it requires a subject that isn't moving. Here are a couple of recent stacks:
This one was taken with the 18-55mm kit lens + 250 Raynox DCR-250, and processed in LR:
This one was taken with the 18-200mm and the kit flash (taken at night).