Hey,

I am looking for an Impressionist Workflow or Filter for CS4.

Thanks

Eric

A free PS filter. Steve L. hosts this gem and I still take it out for a spin often.

http://asnailpace.com/blog/impressionist-plug-in/

A not free stand-a-lone but I believe it will give you the result that you are looking for.

http://www.mediachance.com/dap/index.html

Alien Skin Snap Art 2 has some very nice natural media emulations.