Money's been tight recently so I haven't been doing much of anything lately. I have managed to do a little bit on a proof of concept for a "booster" water rocket. Basically a water rocket with a freakishly large nozzle (2inch PVC). I've put together a plain (as in, single stage only) four liter rocket.

I've also got an o-ring channel cut for a launcher (I'll probably add another) and some fins.

I'm also planning on making a bunch of regular (as in, bottle mouth sized) launch rods. After overthinking the problem for way too long (hey, I've got time and no money) I just keep coming back to two points.
(1) PVC is way easier to work with and...
(2) Schedule 80 PVC is just what's needed for sturdy launch rods.
Schedule 80 (for those that aren't aware) is basically a higher pressure version of regular PVC. It's not made from inherently stronger material...it's just thicker. Since it has to work with the REGULAR fittings, this strength is achieved by sacrificing the inside space. Basically, schedule 80 1/2 PVC...isn't 1/2 inch I.D. pipe. It's more narrow by .076 inches and the wall is thicker by .038inches. I'm just going to use the ol' cordless drill as a lathe to cut out the o-rings. Only takes a minute or two per launch rod that way.