Watch English television shows and try to write down a summary of what is happening during the commercials. In addition to summarizing, though, write down what your thoughts are--this will force you to listen more to what is actually being said.
Have a friend print out the lyrics to an English song, then cut them out and jumble them up. Now, listen to the song and try to arrange the lyrics in the right order.
Have a native English speaker tell you a story. The story can be about anything. Once he or she is done, try to write down what happened in the story, then discuss which points you missed with the speaker.
Ask questions during every conversation you have in English. By doing this, you will keep your brain focused on what is going on and clarify anything you may have missed. When you ask questions, try to summarize in your phrasing a little bit of what the speaker said.