Heres another site, photos taken by the same guy. Dont like the format of the sight nearly as well as I do the one that Dan dug up, but the photos are a decade newer. Intersting to compare the two, Im seeing alot of changes in the bays and estuaries Im looking at, no to mention shoreline development.
Many counties including King, Shohomish and Thurston; and some cities such as Seattle and Tacoma have mapping applications on their websites that include aerial photograph layers. The aerials are vertical as opposed to the obliques on the Ecology website, are zoomable, and include the entire county. The mapping programs are typically accessible through the county assessor's website, gis department, or planning department.
Attached below are two 2002 aerial photos of Lincoln Park in Seattle taken from the King County imap website at scales of 1:9,000 and 1:1,000, and a September 2003 photo of Ben Howard from the Snohomish County Online Property Information (SCOPI) website.