Bayesian networks.

Linear programming - not because it is cool but because it is so useful.

Yes, poorly defined question. I guess electrical engineering and CS has a lot more math and then your specialization matters obv.

How are those places boring? No nightlife(can't be true)?

The Swiss are very insular and unfriendly. The Austrians are a little better. However, in both places it seemed impossible to meet any local person. I will say though that I used to be a skateboarder and hung out in Laussanne, and the skate crowd there was great, as they usually are throughout the world. The nightlife is very strange, IMO. The clubs play a weird mix of pounding techno and horrifying "classic oldies" music. I could not find anything to do at night besides a "club." (In the USA there are coffee shops, or simple bars, or bookstores that stay open late, or even lit parks to play basketball, soccer, etc) No club in these countries were as weird as German nightclubs, though. Vienna does have a large range of classical music type stuff, which is why I was there.

I have not been to any of these places since 2002, so perhaps things have improved. Take it with a grain of salt, I was also just a tourist. In contrast, it's very difficult to describe any aspect of California as "boring" unless you are an angsty teenager stuck in the burbs...

can scandinavians sell apps yet?

But I'm thinking on something small scale, not that needs serious $$$$.

Take a look at waste energy. That doesn't require anything like the startup costs that solar/wind/water requires.

Nope, nothing like that, more like what was posted below. Euler is great for programming exercises though.

The thing I tried this program, ie not a webapp, that lets you fill in your exercises and your meals and then calculates if you on the right side. It lets you put up 10 week plans and doesnt let anorectics use it. Should be something like that as a webapp. I think someone did something like that in Arc.