I've been following the Tumblr of Adventure Time for a while and I'm quite excited about the launch tonight! Even though we have no Cartoon Network and it won't show anywhere here at 8:00 PM like in the US, I'm pretty sure there will be a torrent around with the show.
For those who don't know, here's an episode that has been made 2 years ago by a guy named Pendleton Ward. It is now developed into a series. Awesome stuff, so if you live in the US, watch it!