Is there any comprehensive book/dvd/tutorial on rigging and animating characters (biped and multi-legged) in Blender?
Urgently needed.
Thank you!
Moved to discussion.
Thank you guys. BlenRig 4 is over the top IMO. The purpose of my rigs is real-time games. So it shouldn’t be too complex and it shouldn’t have scaling bones as game engines I am using don’t support scaling bones (actually most of the game engines don’t support bone scaling). Basically I am after complexity of rigs seen in Gears of War, God of War, etc.
I am wondering if JonathanW either can build one for me or train me in rigging 
Blendercookie, http://www.youtube.com/user/BlenderFoundation#p/u/90/9qLk82LFFRc or http://vimeo.com/1184944 I’m pretty sure most things are similar in 2.49/2.5x, at least bone/constraint wise- I know shapekeys have changed however.
You want the (built-in) add-on rigify then. That is what I use for rigging my game characters and it works well. You do need to turn off a few options (to remove unrequired “twist” bones from the generated rig), but it does make setting up and animating multiple characters quite simple.
Well… while it’s relevant to this thread, I think it may be valid to make a shameless announcement about my recently released book on character rigging and animation with Blender 2.5: http://www.packtpub.com/blender-2-5-character-animation-cookbook/book 
More about it here: http://virgiliovasconcelos.com/?sessao=blog&language=en&id=380