Yes, it's not hard to run out of memory. However, PIM info isn't going to run you out of memory. See the FAQ's on how to rid unneeded apps/modules from your device. You can also search for "memory leak" on the forums and you'll find lots of information on memory issues.
I recommend setting up your camera options to save pictures to the SD card. Remove unused languages, the demo video, etc. You can get more info at Main Page - BlackBerryFAQ