Sorry for the bad english i am turk.I want an amplier for my ipod e few days ago and i think it will be portable and simple.I stole amp circuit from a spy toy.
Step 1: Materials
An amplier circuit (You can buy or make one of them)
Battery holder (It will be supply your amp circuit)
Kilometers of cable
A speaker (It will be supply your amp circuit)
3,5 mm male jack
A pocket knife
Glue (hot silicone etc.)
Step 2: Soldering
Solder + in to switch's 2nd pin.Switch's 1st or 3rd pin to battery holder's + cable.This will be power switch of the amp.Then solder 3,5 mm jack's left and right pin to adjustable resistance's 2nd pin and adjustable resistance's 1st or 3rd pin to amp's + in or solder direct to amp's + audio pin .After this solder amp's - audio in to 3,5 mm jack's ground pin.And the final , solder amp's audio out to speaker.
Step 3: Attaching
Attach switch and adjustable resistance to plastic egg by making a hole with knife.Then tight nuts and stick the speaker by cutting top of the egg.
Step 4: Finish
Now , you have a very low tech egg-amp.Sorry for bad pictures.