h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I've thought of some wonderful marketable inventions in my life, but never told anybody who's capable of marketing it because I'm scared that they'll steal the idea. Unfortunately this means that I'm not making any money out of the ideas anyway, because they never get further than my head.
For example. I was sitting in the bath a few years ago (have you noticed that virtually all great theories and inventions have resulted from a flash of inspiration while in the bathroom? Somebody ought to research this.), after a particularly muddy cross-country run, and the bath water was rapidly turning opaque. The soap, as it tends to do, slipped out of my grasp and I spent a good two minutes finding it. I wondered if it would be possible to make a solid foam of soap and air, moulded in a bar shape, and market it as 'floating soap'. I resolved to write the idea down as soon as my hands were not covered in a paste of soap, water and mud; and of course five minutes later forgot all about it.
Until last week. I was mindlessly watching the local news on TV when an item actually caught my attention (This is unusual enough in itself). A local man had marketed 'Floating Soap', basically a solid foam of soap and air, so you didn't lose your soap in the bath. He was making a fortune out of my idea. The fiend!

I realize that this is a fairly late addition to this thread, but what the heck.

There has been a 'floating soap' for rather a long time, at least in the US. It's called Ivory Soap. You know 99 and 44/100 % pure, and all that. http://www.ivory.com if you're interested in learning more, it's a very nice "brochure" site (to somehow wander back to the original topic). There's even an FAQ there, that tells the story of how the soap came to float (hint: it was originally an accident)