First, have you tried a hard reset? (With the blackberry on, pull the batter for 30 seconds or so.)
And do you have a media card? If not, get one. Move your images, music, etc. from main memory to the card.
What do you have running? Do you have programs that run in the background? Pay attention to what you have running. Start closing things that you don't need. Make sure you close the app and not just send it to background.
Look at your free memory. If it is below 10-12 MB, start looking at freeing some up. See http://www.blackberryforums.com/gene...tml#post792173