My wife is an avid fly fisherwoman. I wanted to join her, so I ordered a fly rod and reel off of amazon.com, and when it arrived, I had a distinct worry. I do love the outdoors, and backpacking, so I had ordered a 9' rod that came in 4 sections. When I assembled the rod, it seemed way too long for some of the places I have hiked to (tight corners in the streams, lots of overgrowth and trees covering the waterway). I wanted to be able to hike with a 9' for lake-side fishing, but shorten the rod in a pinch for other places.
Maybe I simply thought that this was a good excuse to head out to the shop.
Either way, that's what I did. I had a chunk of 1/2' aluminum rod from Home Depot from a previous task, so I chucked it up in the lathe and turned it down to an outside diameter 1/8" larger than the ferule side of the butt-end of the rod. Then I turned down one side of it to the outside diameter of the next section (which has a taper, BTW), and then drilled it out to fit over the butt-end, ferule-side. Essentially, it's a lightweight part that eliminates the section of rod that connects to the butt-end, and it fits in the cap of the case.
Granted, it DOES change the speed of the rod. The rod becomes much more stiff down low (which means the rod becomes "fast"). The purpose was not to have two moderate rods of different lengths, it was to have a single rod that could work in a pinch for a different situation. You simply have to change your casting method. It fits, it is extremely light, and now I can pop into odd situations and still spend a day doing nothing (like that's going to happen). I finished the rod up (and also my wife's rod), and I'm ready to go!
Now I just need to set up a time and go on a fishing date with that hot wife o' mine!