here is a really impressive movement tutorial in 2 parts ..
Part one :
http://uk.youtube.com/watch?v=pYcnCWek4aw
and
Part 2 :
http://uk.youtube.com/watch?v=z7dYB64ppnI&feature=related
Part one :
http://uk.youtube.com/watch?v=pYcnCWek4aw
and
Part 2 :
http://uk.youtube.com/watch?v=z7dYB64ppnI&feature=related