A "Berliner" is not actually a jelly or cream "filled" donut, but rather a pastry with a glazed fruit topping (and quite delicious). (If I could ever master posting pics on here, I'd post one)
When I was stationed in Berlin the Germans would say "Ich bin ein Berliner" to be 'cool'... They loved Reagan over there too (except for the hippies who hid out from the draft in West Berlin [draft exempt city]). When Reagan passed there was some movement to name a square after him - I don't know what the status of that is...
I think most Americans would understand the mistake better if he had said "I am a Frankfurter, or I am a Hamburger".
See we have words in English named after German cities. A Berliner is a type of pastry like a Franfurter is a type of sausage.
I think Teddy might go for the "I am a Limburger" line.
RE: Posting pics