High Quality Content by WIKIPEDIA articles! The Sony Ericsson P800 is a smartphone introduced in 2002 based upon UIQ version 2.0 (which itself is based upon Symbian OS v7.0) from Sony Ericsson. The P800 is arguably the successor of the Ericsson R380, and initial design work was done within Ericsson, but it was produced after Sony Ericsson merged their mobile phone businesses.