Rodney

How to make a bottle of shampoo last (seemingly) forever:

When you buy a new bottle of shampoo, save the empty shampoo bottle.

Squeeze about two capfuls of shampoo into the empty bottle (only one if it's a small bottle), fill it with water and shake. The soap will go into solution in the water.

When you shower or bath, put the bottle of dilute shampoo in the bottom of the stall so that the falling water warms it (or, if you're a tough bastard, skip this). Then, after you've wet your hair, pour the shampoo solution over your head and work it in. It takes a fair amount, but you'll get as many as eight shampoos out of one or two "recommended" portions this way. If you're using cheap shampoo, you may not care, but if you like expensive shampoo this method brings the cost per wash 'way down.

When the bottle of shampoo solution gets low, squirt a little more shampoo in it, top it off with water, and shake.

Yeah, it's a little anal, but I enjoy paying a lot less for shampoo than the industry would like me to pay. And you almost never run out of shampoo.