I think Alabama will accept applicants who have a 3 GPA and a 21 ACT, so it is not that difficult to be accepted. I know they must have accepted students with less than a 3.0 and below average ACTs last spring -- I know of two who are currently freshmen.
It is
possible to pledge a sorority at Bama with a 2.8 -- I know several girls who have over the last several years. However, their options were significantly reduced after the first round or two. These were also girls who knew actives in many of the houses.
Chapters differ in what they will accept in terms of GPAs during member selection. The individual chapter GPAs at Alabama vary widely -- some chapters have high GPAs, while some barely have a 3, and a few are below a 3. However, this should not be extrapolated to indicate member selection requirements. The Greek semester grade reports can be found here:
http://greekaffairs.ua.edu/resources.cfm
greekcurious, it would really help if you could raise your GPA to a 3 at least -- it is to your advantage to be as stellar on paper as possible. If you excell your senior year, you might consider listing your senior-year GPA separately on your rush resume, just below your overall GPA (I've seen this done before). This would at least help the alums who write your recs see a trend toward improvement.
As long as you know and accept that a lower GPA will limit your options -- you have nothing to lose by trying. Good luck with it (study hard!).