Bingowings said:

Once again not really.

Artoo maybe for opening the doors (though arguably any droid with the right attachments would do), Han and Chewie for their expertise (though they both prove to pretty useless what with the snapped twig and dead animal gags) but Leia??

The group spent some time putting on camouflage outfits and they brought along Threepio???

Yes that is all true. But they still at least had some role... unlike in ESB where their role was nothing for almost entire film and in the end their role turned into being a bait for Luke.