yes. if you live by an apple store you can do that and you get the added benefit that your powerbook will stay in the store as they order the parts.
one thing to take a look at is "apple pro care" it cost $99 buck a year but it among other things would have gotten your machine back to you with 24-48 hour (if they have the parts in the store) and essentialy puts you to the head of the line in the apple service dept.
otheriwse 7-10 days. (or 3 or 4 via overnight shipping) if you are a pro and can't stand to be without your mac that is one option to think about.