There's uses for infinity: it's what you get when you divide any finite number by zero. If you like, it's a mathematician's way of saying "negligibly large", corresponding to saying "zero" to mean "negligibly small", and, erm, taking it to the limit. (Now whose tune is it I've got running around in my head? sigh.)

One of these days, I'll try to wrap my head around more recent work on the Continuum Hypothesis. There's rumours that somebody has produced a statement which effectively implies said Hypothesis, but is simple enough to be useful as a basic hypothesis to add to set theory.

Oh, and Cantor used Aleph to piss off the typesetters .... whose revenge is that Aleph is printed upside down in all mathematical texts.