From what sources could I find the modern versions of folklore?
Answers
For starters, it depends on what you're asking for. If you're asking for examples, then you should search for urban legends and things like that. I'm not sure what in particular you're looking for, but if you just search for "best urban legends" you'll get loads of really great lists. The website Cracked.com (18+) has a long running series of the best urban legends that happen to be true. Those are good places.
If you're looking for folklore that emerged recently, the only really good example I can think of is African American folklore. This is because folklore tends to emerge at the beginning of a culture's inception and sort of mutate from there. I would imagine that other countries with similar histories, like Jamaica or Latin American countries, might have a similarly rich and relatively modern folklore culture, but I'm not familiar with them. Your local library might have some good books to check out, or you could try Googling some stories.
Now, if you're looking for a modern collection of classic stories, I don't know any specific books besides Neil Gaiman's Norse Mythology, which comes out on February 7, but again, a quick Google search or perusal of your local library should match you with some very well-told versions.
Finally, if you want old folklore in modern settings, there are a few books and series you could try. The Percy Jackson series, by Rick Riordan, takes entirely from Greek tradition. The Secrets of the Immortal Nicholas Flamel, by Michael Scott borrows from several mythic traditions (a lot of alchemy and Egypt, but some others). Neil Gaiman also takes from multiple sources in American Gods and its more focused companion, Anansi Boys . As for television, try Supernatural (in my opinion, it goes to hell after the sixth season, literally and figuratively) or Grimm.
Sorry this is so long, but I wanted to be thorough