How do I save a number that has called me?

Add a contact from a message, call log, or web page
1. In a message, a call log, or on a web page, highlight a contact.
2. Press the Menu key.
3. Click Add to Contacts.
4. Type the contact information.
5. Press the Menu key.
6. Click Save.


taken from: http://docs.blackberry.com/en/smartp...001-5.0-US.pdf