Below are some professional sites worth your time...

www.Pro-ScriptService.com

(Pro-Script is my other writing service)

www.Scriptcopier.com

www.Tailfish.net

www.Inktip.com

www.Scriptmag.com

www.PlugVideo.com

www.WorldWideFreelance.com

www.ScriptPimp.com

www.TheWritersPlace.org