Eeweb wanted to exchange links with me. Like always it sounded like a trap, but no. On closer examination it came out that they host webcomic that I read every week. I just have to link them now: http://www.eeweb.com/rtz . Because I love webcomics.
To not make it too one sided: check out Ohm's Law calculator on the12volt.com. Basically it has calculators to calculate I, U, P and R from each other in every combination. Super useful if you are too lazy to bend the formulas.
And to make it clear, they didn't pay me. I link them and everybody else because I like the content. At some point I thought about putting advertisement on my page to make it pay for itself, but now I don't want any more. There is enough stupid ads everywhere and I don't need that money so bad. Besides, if you are like me, all the ads take you to HobbyKing anyway, so go there without ads and buy their stuff. They are good and cheap.