Ahhh!! Thank you Kasperg...great find mate!!....with a litte bit of extra searching I managed to dig up this...
http://www.hl-improvement.com/index.phpThis is the home of HL:E..."A mod that will give you...Detailed Models, Detail Textures, new Visuals, physics (RagDoll!!) and some extra enemies". ALL FOR HL1!!!
Unfortunatly....they are still developing it...and like any classic mod team will not give a release date. So...hopefully they might release it before Source becomes the norm! According to their forums its all alive and well...but the link below is from last year!!
I managed to get a link for a video demoing the ragdoll physics in action:
http://www.wunderboy.org/archive/2005/03/