Yea... the ''taking a screenshot and cut'n'edit'' solution is
probably the easiest

.
Alternatively, I'd probably be possible to import the Flash
animation into the Macromedia Flash app... and copying the
picture from there... but that involves a bit more than the
other solutiion - also, it's not always possible to just import
the Flash files... if they're protected against that... so yea,
I'd probably go with John's solution too (if I didn't have Flash
installed (and didn't want to install it))

.