The latest issue of BYO suggests setting a submersible pump in ice water and cycling it through your chiller. In light of Jamil's suggestion to chill wort to six degrees below fermentation temperature before pitching and my want to keep experimenting with lagers, this sounds interesting. (It also sounds like a potential new brew toy). Does anyone do this? If so, what size pump, what length of hoses? Can you describe your procedure? Did anyone try it and find that they were unhappy with the results?