Nozzle designs?

Where can I find info of the various nozzles out there? (just the nozzles not the extruders)
I am after some info with measurements and angles to compare so I can see what designs work and what doesn't. Ideally including internal presures if anyone knows.

Is there any form that seems to work well or is it a case of anythign that will squirt plastic is ok by us! ?

The reason I am looking is to mull over ways to make them quick easy and dirt cheap. Prefeably taken from something easy to come by. Like the tip of a mechanical pencil or a biro tip. Has anyone tried these?

the latest designs mostly have a lining of PTFE tubing for the filament to run down. Before this most extruders had joins in them where the PTFE barrel meets the brass, the molten plastic seems to eventually find its way into the joins and solidify causing jams. So I would either have a long extruder with no joins i.e: [www.thingiverse.com] (just make sure you have a heat sink and or fan between extruder body and hot tip. You lose distance this way, with PTFE lining you can still keep the extruder compact.

also i haven't tried extruding 1.75mm yet but i would imagine this would be a different ball game as it would require less pressure... still would line with PTFE tubing though.