For those of you that use Flickr to host your photographs, and are interested, the 2010 Flickr scavenger hunts for signs is now in full swing, awarding points for different signs found. The scavenger hunts are currently being hosted for the following states and regions up and down the East Coast.
New England - http://www.flickr.com/groups/newenglandsigns/
New York - http://www.flickr.com/groups/nysigns/
Pennsylvania - http://www.flickr.com/groups/paroadsigns/
North Carolina - http://www.flickr.com/groups/nchighwaysigns/
It is also a possibility that Virginia may have a sign scavenger hunt as well.