Good question. I mean, I could do what Biff did in Back To The Future, and get a sports almanac, and get wealthy betting on sports I already know the outcome on...or I could get a printout of the biggest lottery payout numbers...
I mean, there's a lot of endless possibilities. Then I finally decided (and clearly, taking something back with me involves less than integrity-driven motives) I would take the Twilight series back with me. And I'd put it out before Stephenie Meyer ever had her dream (heh heh!). You have to admit, the girl had good timing. There wasn't a whole lot of vampire "stuff" out there, and now, that's ALL you can find at the local bookstores.
Isn't it all about timing? I wrote a fairy story last year, and I was excited to submit it, and suddenly, all the books on the shelves were about Fairies! (I guess vampires had their run, and agents were actually saying "no vampire books please" on their websites!). So, naturally, no one wanted to read my Fairy story.
So, now, I'm working on something different. It doesn't have Vampires in it. It doesn't have Fairies. It has a regular girl, no mystical creatures whatsoever, but it does have a fantasy element--Time Travel. I'm not seeing a whole lot of those types of books out right now.
So, maybe by the time I finish these edits, and start submitting, someone will have come out with a GREAT story where a Fairy and a Vampire Fall in love whilst TIME TRAVELING together. And everyone will be freaking out and getting inspired to write about Time Travel.
I sound jaded, don't I?