Check out a page on Guitar Tricks.
Make a list of three songs you'd like to learn, and if they're not on GT, then just google the song with the word "chords" after the name. After you've found your songs, just doodle the melody off the chords. It's great ear training.
Take a song that you already know cold and invent different fills and variations for another eight bars.
Play blindfolded. It isn't easy at first, but after all the clams, your fingers will go to some interesting places.
