30 minute exposure with Canon 5d

Last night was so warm here in Florida and the sky was clear, so I went out to the dock and watched the stars. I wanted to try out my new cable release so I just set the 5d on the ground with a 15mm fisheye lens and got this shot. Its not an amazing photo, but I was just excited that the 5d is capable of a 30 minute exposure without minimal noise. But there is still 2 problems... The in-camera noise reduction takes another 30 minutes so the total time is 1 hour, and after one hour the battery was just about dead. Digital is really close to being great for really long exposures, but I still think film is the way to go for exposures longer than 10 minutes. Ok enough with my photo nerdness....