me4life, what a great idea!
I went around and did the free pass thing, but I ended up deciding to join after finding a place for $30/month! I just can't get motivated when I'm at home--but that's just me.
But as for the treadmill vs. elliptical question, I like that the elliptical is lower impact because your feet aren't pounding down
I'd say that unless you're really into running - which many people are - just go with the elliptical.
As long as that new machine doesn't turn into an extra coat rack