For the uninitiated, the Pliko P3 is a Mamas and Papas model of pushchair, and was marketed as a "city" buggy. It folds small enough to fit into a corsa, (with a huge tent, a baby car seat, and a travel cot!), it has lasted rough use through two children, and still on the go, and has a sort of step on the back to fit a lazy pre-schooler (can't call him a toddler anymore

I haven't a clue how it is manufactured, so it could be a very evil thing, but these go for a song second hand and considering how ours has lasted, I am sure they would be good quality.
The Hamax "Sleepy" - a bike seat to fit on the back of your bike for kiddies, which reclines so tiddlers can snooze in comfort (or faint with fright as I suspect was the case)
nursing bras - clippy bits to release one massive milk laden boob without revealing the whole rack
digital cameras - saves lots of paper???
internet/ebay/freecycle - second hand shop on your lap (but very addictive)