I dont know why it took me so long to figure this out. but first off I recommend everyone get their hands on quick player 7 pro. this media players allows you to set locations within a video on a loop so that you can hear the same portion of video over and over again until your years can adapt. this is such a great tool.just concentrate on those couple of sentences giving you trouble and let go on a loop as you sit back and listen for 10-20 minutes.
next go to you tube and find videos. I highly recommend kureyon shinchan and atashinchi
they are both funny only about 7 minutes long and there are tons and tons of them.
found that juicy video yet? great copy then link and then go to this website to download your video
http://keepvid.com/ you now have it on your desktop. open up with quick player pro and set short segments for your listening practice and look up new words from video as necessary. if you can get a transcript this makes it even easier as you can use rikai chan to speed up your look ups.
have fun. I have been increasing my vocabulary big time recently watching national geographic videos in japanese with a transcript typed up for me by a friend. the videos are only 2-5 minutes long but stuffed with great vocab. might as well learn and enjoy while learning the language. cheers