Trulia lets you search ’em.
Zillow lets you talk about ’em. (Love the contextual advertising!)
Now Hotpads lets you map ’em. Very cool (and scary, depending on where you live) feature on Hotpads lets you map, county-by-county, the number of foreclosures near you.
Just click on Heat Maps and then choose Foreclosures by Capita. High number areas are colored Red, cooler areas are colored light blue.