We saw proof eariler that Liberty City may have a mutant problem. However, it looks like San Andreas was GTA's Tasmania* a few years before it. If you check out the above picture (larger version after the jump) you'll see the middle gang member has at some point sprouted a fifth finger. That, or he has the world's most awesome thumb.
The photo here was taken from a poster reader Grant picked up during his time at EB Games. Thanks man!
UPDATE: Here's the full image for comparison.
* Sorry to Tassie. It's a great place, lots of trees.Click here for the large version.