That's super awesome! I'm actually working on some code to consolidate all my images from various drives in to a single location, then sending them to flickr...cuz 1TB!
If you're interested i'm actually creating a hash of the image contents, I wrote some functions for powershell, that i'm working on flipping over to c# since i'm moving all my powershell dev to c#.
the function is get-bitmaphash
it uses system.drawing to load the image into memory then I just use cryptoserviceprovider to compute the hash from the memory stream.
There is some other stuff that will pull gps data from the exif tags and give you coordinates and such.