Accent Archive
As a perfect example of the kind of thing that just wouldn’t happen without the internet, I give you the speech accent archive. Basically, it is a bunch of random people from all over the world reading the same sample script in English. So if you are trying to figure out what a Madrid, Spain accent sounds like, as compared to a southern italian accent, you can listen to the various samples and get an idea. The execution isn’t perfect, it could stand to have more than one sample from a location, and I would like to hear different text, but still it seems to be pretty useful.