I know a bit about it, it was considered a possible diagnosis for me at one time. Turned out I had MS, not porphyria...but I had researched it before it was ruled out.
Here’s a couple forums...I found forums helpful when seeking info from people who actually had experienced the disease.
http://www.mdjunction.com/forums/porphyria-discussions
http://forums.wrongdiagnosis.com/showthread.php?t=4297
http://health.yahoo.com/search;_ylt=AqSjkplDHWLh5nHPlU96Mguz5xcB?p=porphyria
we are still waiting for the second round of labs. She has each and every sympton including the red to purple urine during the attacks