As a followup, my instructor said that the calculator only needed to be able to do 1 variable statistics, linear regressions, etc. He recommended either the TI-30x iis or the TI-83/84 series. I could've used my HP 48, but none of the demonstrations in class would use it. On the upside, NONE of my classmates have any idea how to use Reverse Polish Notation, which is a shame.
I bought the TI-30, since it was only $16. It does ok, but it's very tedious to enter lists. So yesterday, I bought a new TI-84 Plus CE. The time saved in entering lists and data made it completely worth it.
And on the upside, when my 6th grader gets to 8th grade, he'll need a TI, so he can have the new 84.
I did break out the 48G and let me 17 year old daughter try it. Very funny to watch. And I also pointed out to her that the HP was older than she was.