Got one of these for my Dad but I'll have to get another one now! I opened it to have a look, but a little tin full of wires and LEDs and stuff is impossible to leave alone. I pretty much went straight to building the first circuit which I finished probably within about 20 minutes or so (there are plenty more circuits to do and they get more and more complex). Each of the projects produces an actual working thing, which is great - but you won't really get to use it as a cookie jar alarm or egg timer, simply because you will want to straight away take it apart to make the next thing!! What I really liked was that it wasn't just an 'electronics-by-numbers' kit, you really learn because the instructions explain what's going on in the thing you're building.