I have a netduino lying around. I wanted to get into that sort of stuff but I quickly found that I don't have enough knowledge of electronics. I then bought this book to learn the basics, but found that there's quite a steep learning curve between really basic stuff like Ohm's law and more advanced things. Also, I then realised that if I bought all the things I needed for the experiments in the book I'd have to spend hundreds of euro's.
Also I was blowing up LED's like crazy for some reason.
It's too bad, I still have a bunch of ideas I want to try out. There's something fun about the idea of seeing your stuff work "for real" instead of just on a computer screen.