Nice, thanks guys. I was pretty sure about the Old Man's Beard. I think swords might be closer on that one, though - it's fuzzier than Espostoa, the lobes are further apart, and the spines are red and more pronounced. I think the smaller round ones are some manner of barrel cactus, but there's at least two types there. The one with criss-crossed spines is intriguing.
The two that really confuse me are the one with the long hooked spines and other with short black spines (which, by the way, give extraordinarily itchy scratches.) Kalanchoe tomentosa was also a first bet of mine... fairly certain it's some sort of Kalanchoe at least. Any other help would be great, although this should already be enough for me to at least make some preliminary tags. Thanks again!
~Joe