One of the players who played for both arsenal and Liverpool is Nikolas Anelka ( also played for chelsea , West Brom ) Another Player is Yossi Bennoyoun
Nicolas Anelka has played for both liverpool and chelsea.He has played for chelsea from 2008 to 2012.
Michael Owen has played for both liverpool and currently Manchester united
Footballers to play for both are Jesper blomfentien and david Beckham.
It is close between jay Jay Okacha and Kanu, both played for years.
Nicky Barmby, Abel Xavier
Jermaine Pennant Nicolas Anelka
One such goalkeeper is Sander Westerweld, who played for Liverpool between 1999 and 2001, and Everton on loan, during a 2006 goalkeeping crisis.
It could be Peter Beardsley.
albert riera and robbie fowler
Only Nicholas Anelka that I can think of from recent times.
Nick Barmby Peter Beardsley Able Xavier Don Hutchison Gary Ablet Im sure there are plenty more, but none that I know off........