I believe if you join the army you get them for free :-)

Sets of punches are available on ebay...

http://search.ebay.com/search/search.dll?from=R40&_trksid=m37&satitle=le...

...these would let you make your own using recycled tin-cans - or use these

http://search.ebay.com/search/search.dll?sofocus=bs&sbrftog=1&catref=C6&...

One of the gift shops at the National Museum of American History has authentic WWII dogs tags which they personalize, and I seem to recall they were around $5 each. Unfortunately, the museum is closed until next summer, and this particular item doesn’t seem to be available in the online Smithsonian shop...

thanks for theb suggestions

Don’t tell anyone, but I was in a Wal-Mart the other day (I didn’t buy anything...I swear!) and happened to see a ’child ID’ vending machine that appeared to make dog tags.

Otherwise, walk down to the local National Guard Armory and ask if they’d make you a bunch.