What are your laptop specs and what is the rating of the battery? If you're running Vista, changing things to the Power Save mode in the Control Panel can do wonders, and if you have a non-Intel video card, it helps to try other drivers as well. But still, for a laptop that's pretty bad. They should at least run for 2 hours unless it's a power hungry thing such as those "gaming" laptops.
What also helps is to boot the laptop off the battery and then plug it in once Windows starts loading. That will downclock both the video card (if it's one that supports doing so) as well as the processor. My 11 year old laptop when on battery if I had Intel SpeedStep enabled in the BIOS would downclock itself from 600Mhz to 500Mhz if I booted it off the battery, and would not go to full speed until I shut down the laptop, counted to 3, and turned it back on. It did give me 20 minutes of the battery by doing this.