Hey can anyone tell me how to use a renderman renderer with blender? Preferabley 3Delight, but it would also be useful to know Aquis and Pixie

The main integration of Renderman is going on here

There are also other export scripts like BlenderMan and Blend2Pixie scattered around.

It all depends on your work flow. I personally use Pixie and wrote myself a very simple script that exports only meshes, since I do all the lighting and shading in renderman.