This is a free Horse rig I have created for Blender 2.5 (Alpha 2)
here is a video explanation of the rig:
This looks pretty neat. Can you save the blend file in v. 2.49?
sorry, but there is a fair bit of work to make it backward compatible
and it won't have all the visibility features or the bone layer buttons
plus the IK/Sliding will need to be redesigned
just DL 2.5(Alpha 2) - some buttons are in different spots but it is much easier and faster than 2.49 once you know where they are
All the bones that have the _DEF suffix are the deforming bones (except for the Tail and the head which doesn't have the DEF in the name)
the DEF bone are all located on the right side bone layers
and usually mirror where the control bones are located on the left side layers
(eg. if the control bones for the Front legs are on the layer 4 from the left on the left side - the DEF bones are located 4 from the left on the Right side)
you will need to weight paint your model with the vertex groups names
a good start is to parent your new mesh to the armature with automatic weigths
this will create all the vertex groups - and then you can correct the weighting manually from there
This may sound like a stupid question but how do you download it and get it onto blender?