Ask HN: What are your web app ideas?

Hey guys,

I'm looking for ideas for a web app, that you want to build, but just don't have the time for. At this point in my life I am of the belief that ideas themselves are worth very little, and having somebody else interested in working on it with you may either spur you to work on it yourself, or at least get your idea manifest into the real world.

So, if you have a great idea that you don't mind getting stolen, post it here!

I'll go first: I think it would be neat to build an easy-to-use web calculator, so high school kids could do their math homework without having to buy expensive calculators. I am actually considering this: it's not too hard to write a graphing interface in Calculus, or write tools to do things like Linear algebra, derivatives, calculate integrals... anything more advanced justifies using a university Mathematica license or something :)

What do you think of my idea? What are yours?

Zack