A lot of the orgs that were in Phi Sigma Phi dropped out relatively quickly for varying reasons. On my last campus, there's a chapter that never joined it - but is a local that was once an Epsilon chapter.
UW-Platteville Phi Sigma On the UW-Milwaukee campus, there is (was? they're going defunct from what I've heard) chapter called Phi Sigma Delta - used to be a PSK (and possibly PSE) chapter as well. I always thought it was interesting that the Phi Sigs from my school would go hang out with the PSDs and other PSK chapters and were totally accepted, even though they aren't a part of the national anymore.