ohhhhhh now i just figured out why i couldnt find PS alpha channel controls!
there are none!
in gimp theres this really easy way you just go "color to alpha" and select white, and boom white is now transparent. very good for effects like in my second halo sig where you really cant efficiently go around with the magic eraser
correct me if im wrong though
oh and so far thata pretty much the only difference ive observed between the 2 teh menu layout and everything is mostly the same so most PS tuts work the same in gimp