Keep track on active slide
Maybe using jQuery's $.data() to store a bool variable or something like that. 

Also you could store a global variable with the active position (e.g. "3" for the 3rd item in the gallery), and then change it, using it along with the :eq() selector.

Either way, I think that the .active class approach is very useful because it gives you the chance to alter the CSS properties for that specific item on your gallery.