Yellowstone

[pheniox17]

yep I'm still chasing more info on this...

and any other super volcano you can think of

[Pauls]

There are at least 6 other super volcanoes - two of which are in the US.
These are the ones other than Yellowstone:
Long Valley in CA.
Valles Caldera in NM.
Toba Caldera in Sumatra - even bigger than Yellowstone
Taupo Caldera - I forget where it is
Aira Caldera in Japan
Phleggraen Fields in Italy?? - this one looks like it is in the lead up to an eruption.

A super volcano has to be capable of an eruption that will displace at least 1000 cubic kilometers of ejecta into the atmosphere. (around 600 cubic miles)