Any advice for kind of a last minute (read: 3 days from now) need for a decent but budget hotel in Amsterdam? Thanks!
did you look in RS Amsterdam Guide Book yet?
If you don't book anything before arriving, go to the VVV - The Netherlands' tourist bureau - when you arrive at the airport. They speak English and can arrange for rooms at a number of places.
Head over to http://www.kayak.com and do a search. Hotels fill up fast on the weekends in Amsterdam year-round. There is more availability mid-week and its cheaper as well.
Check out the Quentin Arrive Hotel and Frederic Rent-A-Bike, which has a lot of properties.
Also, look at priceline.com, kayak.com, laterooms.com.