Naked Nokias: the 5165 on the bottom is the oldest, with bulky, less integrated components populating both sides of the board.  Moving up to the 3360, and the 3595, all of the electronics are on one side of the board, under the metal shielding.  The other side of the board has the receptors for the buttons.
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/44124348109@N01">Steve Jurvetson</a> from Menlo Park, USA
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/jurvetson/7699598/">Nokia Progression</a>