Before you go see the movie, you might want to read this article. It explains all of the little clues from other Marvel films that have been leading up to the GOTG movie. It's especially helpful if you're not a reader of the comics.
Well, I know where I am going to be tonight! See you there, VampChix!
Update: You guys, it was awesome! Hilarious, exciting, and oh yeah- we are totally going to get a crossover with the Avengers eventually. I can see all the pieces coming together. Gah! It will be epic! Must see.