British Anna Friel, who plays Chuck, uses her American accent all the time when on set. The only person she will drop it for is her mother when she calls as she can't stand her daughter using her "American voice".
After ABC canceled the show at the end of 2008, the last three episodes of the 2nd season remained unaired until German TV-channel Pro7 aired them in March 2009. This means, the last three episodes of the show had their world premiere on German television and were not aired in the US until May 30th through June 13th 2009.
Bryan Fuller wrote the part of Ned for Lee Pace, but his agents declined it. Fuller then offered the role to 'Adam Brody' who turned it down because he was not looking to do another TV series after The O.C. (2003). Finally, Lee Pace's manager went around his agents and told Pace he should read the pilot script. Pace read it and accepted the role.
In the UK the show aired on ITV1, who only had room in their schedule for the usual 8 episodes. Because there are actually 9 in season 1, ITV1 didn't initially air episode 2 at all, until after the season 2 finale. (ITV2, not widely watched, had aired it after the season 1 finale)