one way of improvin your rhythm is to listen to stuff that has a very strong rhythm. i used to listen to nirvana etc, an had the worst sense of rhythm, an when i moved over to listen to more acoustic style where rhythm was essential part and possibly made the song (think of george michaels faith i know its not great but it is jst the rhythm the guitar is playing which makes the entire song) by listenin an movin to it (essential!!!) you will start to gain a more natural rhythm in your playing as well. this an practice so you feel comfortable on the guitar, and practice more complex rhythm on your guitar, try playing off the beat or anythin that doesn't involvejust playing du du du du du du du du du du all day long! an learn to dance! haha but thats just to impress!!!