Complete BlackBerry Secrets Blog

Blackberry 8xxx series have 64 MB of internal memory, which is used jointly by the Operating System, RAM and Storage System ... if we use OS ver4.5 with a standard installation, leaving only about 24 MB. And if it used long enough, usually will begin to slow down when the rest memory below 10 MB.

So to free up some memory try to do this step :

1. Install the necessary applications only, there's no need to store application that you only use it once.
2. Avoid to install applications that are continuously running, such as Google Mail or Yahoo Messenger, install what you need the most and do not activate the automatic connection ...
3. Do not keep unimportant emails.
4. No need to save the Chat History Logs of YM, GTalk, BB Messenger, or any other.
5. Restart BB if it started to slowed down.
6. Remove battery for a few minutes if restarting didn't have any effect.
7. Re-install your BlackBerry OS, and just choose the necessary ... example:
- Do not install language2, MDS, DOD Certificate, Password Keeper, Blackberry Maps if you dont have a GPS, BrickBreaker, Document To Go.
How to reinstall can be read here
- just install: BlackBerry Messenger, BlackBerry Attachment Service, MemoPad, Tasks
8. Install MaxMem via BlackBerry ... open the URL: http://mobile.blackberrytrade.com
By MaxMem, we can dispose : Themes that're not used, PTT (Push to Talk), Voice Activated Dialing (VAD), MDS, Ringtones. And it is relatively safe. We can uninstall this application after used.

Related :
How to Upgrade / Reinstall BlackBerry OS