I can't remember if I read this in the In Fisherman, or Field and Stream a year or so ago but it really works well for gullet hooked fish. It will save lots of fish that would otherwise have died or had to be taken.
Obviously time is of the essence if you are catching and releasing so act quickly.
1. First thing to do is cut your line leaving you enough to work with, about a foot is plenty. Pulling the line slightly taught while looking at the hook should help you determine which direction the hook is facing.
2. If the hook point is facing to the left for example, then grab the line you cut, (still attached to the hook) and carefully pass the line out the left gill opening avoiding contact with the gills. The most rearward part of the gill is where you want to go through so you can stay clear of the gills.
3. Now pull on that line at about 90 degrees to the side just hard enough to pull the hook so it faces that direction. Now the bend of the hook should be more exposed than previously. Put your forceps or needle nose as close to the bend of the hook as you can. If you pull in the opposite direction, in this case to the right, you should be able to pull it right out!
I was absolutely amazed at how simple this is and how effective! You are basically just getting the best possible angle for removing the hook. I have used this 3 times already, not on my fish, on other peoples fish and was impressed each time. Spread the word.
The reason I mentioned that it was on other peoples fish is that they are not catch and release types. I am a huge advocate of CnR fishing but don't force it on anyone. But it seems that once you fish that way, you will almost never gut hook a fish. It's a given that everyone's primary concern is to catch fish. As a CnR angler, your concern over the welfare of the fish is higher than worrying about one getting away. My one friend was so worried that he would miss a fish, he'd let it take the bait or plastic worm for way too long and then he was suprised when he'd gut hook them. That's how I got good at the new method.
He practices CnR too now. hahhaha