Nina, you might want to think about this a little. It certainly would be possible to do a crackle finish on a wall but it would also be very difficult to undo. When you tire of the crackle finish, you will be left with a BIG sanding job. You will have to either sand all the crackle off the walls or spackle the wall and then sand all that. It is not a process that I would enjoy.
If you are looking at crackle finishes for more reasonable projects, Franklin International, that makes Titebond glues, has new products out for this. I don't know if they have the info up yet at www.titebond.com but you might check. I saw it at a Rockler store but it was so new that they had not received any feedback from customers.