Jamie Bamber (of BSG fame) auditioned for the role of Jaime Lannister in HBO’s pilot for Game of Thrones, a part that ultimately went to Nikolaj Coster-Waldau. This was revealed by him to Jackie, who reported it at the A Song of Ice and Fire Forum, at the Cylon Attack convention this past weekend in London.
Bamber would have been interesting in the role, although Jackie speculates that perhaps his average height ultimately weighed against him when the character of Jaime is supposed to be tall. That said, we know from remarks from GRRM and from at least one actor that has auditioned that the audition process leads them to keeping in mind actors for future roles. If the series goes forward, we may well see Bamber in a secondary role later on.