There's definitely something magical about being in a Belgian bar and having each of the 100's of brands/styles of beers served in their own distinctive glass.
Bed Bath & Beyond carries the Libbey Poco Grande which works great for serving Belgians. $10 for a set of 4. My local store didn't have them in stock but they ordered them for me, delivered to my house and waived the shipping charge.
It's actually German law that all beer be served in glasses with that fill mark, and (technically) they must fill to that mark. The volume above the mark is for head space.
If you go to any German festivals, or really busy bars (especially bars that cater to Americans) they will often try to short sell you on the beer.
I've even heard of "sting operation" type stuff, where they try and catch suspected "short-sellers."