Best solution is Neoscene from cineform. It even scene detects HDV for christ sakes!
however if you don't have Neoscene the cheap alternative is using DNxHD from avid here is a nice tutorial on how to batch convert your stuff.
Neoscene:
These quick little solutions help you edit faster. I highly recommend neoscene because its such a complete product. It should be in every filmmakers tool box.