As a researcher, I’ve wanted a site like whichtest.info for ages. By answering a few simple questions about your data sample, the site helps you figure out which statistical methods to apply. It’s not a replacement for stats classes, but it’s an incredibly helpful supplement. (Or, if you’re like me, it’s a good way to confirm that you’re actually doing what you meant to!)
It’s also reminded me that there’s lots of easy, relatively low-tech tools for thinking that no one’s built yet, because no one’s seen the money in it – or has gotten sufficiently annoyed to roll their own. Just last week I had to pull out my stats textbook to check something and got really irritated by how long it took me. Next time I’m annoyed at something in my daily life, I’ll pay attention!