iplayer
uses the same software (my pc gets confused if i start using one after periods of using the other) at least with 4od you can stream instead of downloading
(cs192 how appropriate, your mother fights like a cow, Wed 2 Jan 2008, 19:35, archived)

Beeb does a Flash player too now
so you don't need to install anything and/or use XP, IE and WMP11.
( Kamikaze Stoat balanced for lean, Wed 2 Jan 2008, 20:08, archived)