This detects identical files in the current directory and lists the name of one of them for deletion.

Of course, it won't detect the same image in two different formats (.jpg -v- .png), or the same format at different levels of compression, or 8-bit -v- 24-bit color etc.

wrapped for posting...quoted for win32

perl -MDigest::MD5=md5 
-000le" print for grep{ ++$h{ md5( do{ local @ARGV = $_;<> } ) } > 1 }
+ 
map{ glob} @ARGV" *
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