I found this tiny(absolute tiny) and wonderful utility for windows mobile.
It uses top 2 pixel row of your screen and shows you the battery as well as memory status. A quick look at the phone will give you an idea that how much battery is remaining and if you have enough memory free or not.
See the top 2 pixel of the screenshot
Size: 3584 bytes
Put this in your windows mobile startup and have fun. I'm loving it :)