D3Smartie,

I believe around here the saltchuck guys call those "release sticks". I think that they're essentially a couple of feet of dowel with an open screw eye on the end.

You put the eye over the leader, slide it down to the hook, and it slides right out. This works especially well since saltwater salmon fishing requires the use of barbless hooks.

I hadn't thought of using one in a river, I think I'll give it a shot next fall...

Fish on...

Todd.