i've got like 100 circuit of different types too, but whenever i want to build something, i don't have the parts, long lengths of un-insulated wire, push buttons...etc

Are all your cameras of the same type you have pictured? As I've mentioned, the kodaks seem to have the annoying property of having several different PCB contents, so as soon as you do something like design a PCB that uses the parts from one of them, you'll stop finding that particular PCB in your cameras!

Here are some things I've been meaning to do with disposable flash parts.
First, there's a multitude of things within the field of photography:

• Slave flash.
• Make electronically triggerable (opto-isolator?) for safe use with digital cameras.
• ring flash (6 to 8 flash tubes in a ring?)
• Sound activated flash. (been done, but still cool.)
• multi-flash for camera. Several individual flashes during a sub-second interval, to give you "strobed" appearance photos.
  

Other hacks:

• Generalize the "electronic triggering" into something compatible with microcontrollers.
• Xenon chaser; using several electronically triggerable modules.
• Ultimate illuminated staff/lightsaber/etc ("5W LED? Child's play! A mere 5 Joules/second. Mine uses 8 Joules in about a millisecond...")
• "Lightning" special effect machine (I've seen this asked for several times in various places.)
• "Flash bombs" (timed, remotely controlled, and triggered.)
• Low voltage "marx generator." (A marx generator uses spark gaps to discharge caps in series that were charged in parallel; a noisy and fun voltage multiplier. I figure a Xenon flash tube is a sort of low-voltage triggerable spark gap, so I should be able to make a similar device.)
• Magnetic parachute ejection for model rockets. (This has been done. I want to do it smaller...)
• There are some other power-supply-like circuits that involve re-winding the transformer to produce lower voltages...
  

You're welcome to do any of these first, if they strike your fancy; my plate is a bit full :-( PM if you want more info on a particular idea.