Not wanting to risk contamination from fooling with ice packs and such, I just went to Home Depot and got a few coils of copper tube and made a chiller and a pre-chiller. The tap water is fairly warm here in Florida, so this setup has the first coil immersed in a bucket of ice and water, and the second coil used as a standard immersion chiller in the hot wort. Connected these with clear hose right over the copper ends. Less than the price of buying one commercially made chiller. Cleaned the whole rig in vinegar before the first use, and I made the coils so that they fit together decently for storage.
It cooled down a 4 gallon batch from boiling to 80 degrees in less than 15 minutes (approx but very fast) I was amazed. I then used it again to cool some boiled water down to top off the fermentor. Some poor pics can be seen at www.spearfishingspuc.org/Galleries/Kegerator/index.htm