I have a cheap spinning setup and it's relatively lightweight on its own, but I'm not enough of a fisherman to spend big bucks on a lightweight setup.
I focus on carrying the bare essentials. Look at everything you want to have with you and determine what you need. The heaviest part of my tackle box is my pliers. When I backpack, I already have a multi-tool so that eliminates that need. I have a smaller, plastic sectioned box that I got at Walmart for less than $10 that holds enough for me. I always have hooks, crankbaits, spoons, various lures, extra line, swivels, lead crimp sinkers, small bobbers, and rope to keep my catch in the water until dinner!
I keep that plastic case in a ziploc bag since the artificial lures have a tendency to leak some lovely sticky juice over everything. I keep that case inside my pack and strap my rod to the outside.
I either use a fly rod or an ULTRA ultra light spinning rig. Rooster Tails are deadly for small bass and perch. For big bass, rubber baits like lizards or worms or big top water brush popper flies. The size of a field mouse. The rods store in florescent light protector tubes (home depot). Lures/tackle store in a very small plastic box, maybe 1" thick, 6" long. The tricky part is the rod. I have one dual purpose fly/spinning rod that breaks down into six sections. The action is horrible but does the job. Most ultralight spinning rods don't break down so you either carry them whole, or cut them down and install sleeves...a pain, but possible. You'll need to find a place that sells rod making supplies. There are some very tiny spinning reels out there, shop around.
Loc: Gateway to Columbia Gorge
Check Cabela's online catalog. Now this was for fly-fishing for trout, but I found an awesome 5-piece flyrod there for my grandson. Its action is so great that I almost kept it for myself! It's very light if (as I did) you make a case from a piece of plastic tubing with end caps instead of the heavy metal case (containing lead, aargh) that came with it.
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey
I've seen those, Mouse....I'm talking about the 4-5 foot ultralite spinning rods. Those are usually one piece. Probably someone, somewhere makes a take down version but I'm not willing to spend the money for one. There are "travel rods" that are very short, 18in, that actually work very well for hiking creeks, and are indestructible. Haven't bought one yet. Some are telescoping, some look like retasked car cell phone antennas. Like this: http://www.emmrod.com/
Loc: Ozark Mountains in SW Missouri
I have one of these Cadillac Telescopic Fishing Poles that also work pretty well as a hiking stick and tent pole. I think it'd work pretty well for mountain lake and stream fishing. I also have a Coleman "Pen Fishing Rod":
These are very inexpensive and light too. Not the greatest fishing rod or reel, but I've caught enough fish using sticks, cane poles, and a bit of line to not worry about having top of the line stuff.
Of course, I also have some top of the line stuff from the 1980s when I used to fish a lot, but it's not well suited for backpacking.
For bass, if you're going light, flies will really do quite well. I've fished for many years for bass (both largemouth and smallmouth) with conventional equipment, and here are a couple tips: On conventional equipment, spinnerbaits, shad raps, and plastics are my best producers. For packing, I use an Ugly Stick Pack Rod. The action is about like a somewhat stiff rubber band, but it sure works.
Fly fishing, I have a six piece Cabela's Stowaway 8wt. Clouser minnows, wooly buggers, and other baitfish patterns have done best for me. Just a couple days ago I caught an 18 inch bass and a 14.5 inch catfish on a size 14 gold bead hare's ear! I am starting to experiment with terrestrials (grasshoppers, spiders, etc) and they are OK in the right situation as well.
Panfish really like the terrestrials and small minnow pattern flies. I've caught plenty of them on some of the trout-oriented wet flies I keep around. Again, the gold bead hare's ear works wonders. Ant patterns also do well. Most of the biggest panfish I have caught (bluegill in the 9+ inch range) were actually on fair sized wooly buggers and clouser minnows.