If your Blackberry is acting up and deleting your call logs and Email, it might be that it is running out of memory.  To free up some memory, try these five tips:

1. Use the Bluetooth feature to transfer all your pictures to your personal computer.  Don’t keep pictures in your Blackberry (they take a lot of space).
2. Delete unused applications:  If you review your Applications list I bet that there are at least five or six that you never use.  Delete them by doing the following:
   
   • Go to Options → Advanced Options → Applications
   • Highlight the application you want to delete.
   • Delete
3. Clear the web history and web content cache every few days.  This is how you can do it:
   
   • Click on the browser icon
   • Press the menu button and click on Options
   • Click on Cache Operations
   • Click Delete History
   • Click on “Clear” next to Content Cache
4. Delete Blackberry’s Sample Video:
   
   • Go to Options → Advanced Options → Applications
   • Highlight Blackberry Sample Video.
   • Delete
5. Delete Email every two or three days: Trying to stay up to date with our Email and deleting messages more than two days old is a good way to free up phone memory (and to keep our sanity!)

If you have other tips, please leave them below, in the comments section.