Harry Potter: The Exhibition will be making a stop in Seattle, Washington starting in October.  According to the press release:

Soon Harry Potter fans in Seattle will get the chance to step inside the famous wizard’s magical world with Harry Potter: The Exhibition, which opens at Pacific Science Center on October 23, 2010.  Tickets go on sale to the general public on August 14 at 9 a.m. Museum members can take advantage of a special pre-sale opportunity beginning at noon on August 10 through 9 a.m. on August 14.  Harry Potter actor Matthew Lewis, who plays Neville Longbottom in the film series, was on hand today at the Pacific Science Center to kick off the announcement.

In the exhibit, guests will be able to experience dramatic displays inspired by the Harry Potter film sets and see the amazing craftsmanship behind authentic costumes and props from the films.  Harry Potter: The Exhibition will run in Seattle through January 30, 2011.

Thanks to Warner Brothers for emailing!

UPDATE: The first photos of Matt can be found at Matthew-Lewis.com!