I wanted to start a couple of threads describing some new tackle/techniques that have been mentioned recently. Thought this would make for an easy way to search...
Here's my shot:
Freestyle jigging appears to be a freshwater version of "Butterfly Jigging". "Freestyle" may be the Bass Pro Shops name for the same tackle & tactic. These are long thin vertical jigging spoons, similar to diamond jigs but the difference is in the the way the hooks work. Instead of a treble hook, the freestyle & butterfly jigs typically have 2 single hooks connected to the jig by a flexible wire. The pics I've seen have the hooks hanging from the head of the jig body, at the same place the line is connected. The dual separate hooks and flexible wire make for a lure that is often connected to the fish in 2 places and much harder for the fish to gain leverage against the jig, which is cause of frequent lost fish with traditional jigging spoons.
Freshwater versions range from 1/4oz to 1oz
Saltwater versions range from 2 to 9 ounces, 3.75 to 6 inches long. Very good for very deep jigging as the lure gets down fast.
There is a line of Shimano Butterfly jigging rods which are built specifically for this technique.
Here's a couple links to reports/blogs where this lure/technique has been used:
Topsail Angler - Offshore Butterfly Jigging Zooker - High Rock Freestyle Jigging (the rock 1-19-08) Butterfly jigging video from the Tex's Tackle team (Butterfly jigging video)
(Feel free to chime in, correct, enhance...)
Here's a couple pics: