I bought some dimmable CFL's.. Neptune is the brand. THey are for my can lights.. so R30 design. However, if I plug them into my can's or lamps, I get nothing. Is there something special I need for dimmable CFL's to come up?

If the system is a couple of fixtures try swapping one out for a standard incandescent and see if that works. If it does then the dimmer doesn't like the CF's, most dimmers I have come across do work with CF's but some won't ever turn on unless they see a resistive load.

The dimmers for cfl's on the market today don't work well. I've tried 3 and finally came across one that works. They claim to be the only one that guaruntees to work with CFL's. It's worked for me. I'll pm you the link to them.

Some dimmers will fail under CFL loads (dimmable or otherwise.) Edison-base (screw-in) CFLs marketed as "dimmable" should (sorta) work with most though. I've never seen Neptune CFLs. I have dimmable GEs and TCPs in my house- dimming quality crappy (using standard Lutron incandescent dimmers), but dimmable nonetheless.

I had some dimmable 20W twistys (not R30s) once that dimmed better, but made a lot of audible noise at some dimming levels- couldn't stand the noise.

Dimmable fixtures with good dimming ballasts that use 4-pin CFLs and purpose-built dimmers work GREAT, but they're not super-cheap, and a real hack to retrofit. For retrofits I'd go with Cree LR6 LEDs (which do pretty well with most incandescent dimmers) before I'd start swapping fixtures.