Depends on your definition of "really cool stuff" you will be fine with soft corals, most LPS corals and SPS will grow but will not obtain some of the more spectacular colors that they would under MH lighting. but there are some SPS that will do fine also like digitata. you can get green, red, purple and Orange for this coral under PC's. I wouldn't recommend clams or anemone with out MH lighting though. Caps will also do not to bad under PC I have found.

So if you want to do a mixed tank with mostly soft/LPS and some digitata for the SPS then you would be fine. here is a pic or two of purple and green digitata. Digitata will grow quickly also if you keep your Ca at 400ish and your Alk a little higher than normal.

http://members.shaw.ca/cyltic/temppic2/purple.jpg

http://members.shaw.ca/cyltic/temppic2/green.jpg

Steve

Thanks Steve. You are right on the clams, mine lasted only 2 weeks, however I have a bubble rose anemone that seems to be doing quite well.
thanks again.
Greg

If you feed your anemone they can do well in lower light.. I don't feed mine and it does Ok under PC's but I don't recommend that as a rule.

Steve

I do feed it everyday. It is quite entertaining and the crab who lives in it seems to enjoy the ride. I just added the 4 ft pc unit from my cichlid tank and it really brightened things up. Still not as bright as MH but is makes a noticable difference.
Thanks,
Greg