It must be the same as in other Nokia phones with 'alpha-numeric'-only keypads.
In text-entry mode, press the space key (mostly ' 0 ' key in Nokia phones) thrice in quick succession. The text field shows the enter sign (down-and-left-point arrow), and the cursor switches to new line.
It works both in dictionary ON & OFF modes.
Message Edited by Chetan_Rao on 11-Jan-2010 10:57 AM