>It's amazing the amount of Yiddish we, even in England, speak regularly: "it's a bit of a schlepp", "he's a schmo/schlemeil", et al (forgive spelling). I love it. Many a put-down expression.
We have a special type of problem in that area - we got many of these words straight from German, and then some of them through Yiddish or through the mysterious meanderings of slang (just like some of the oldest words in our slang originate in Roma language).
For one, "schmo" is something we immediately recognize by sound: "šmokljan" (schmokliun) is the rolled-up guy. "Schlepp" is even a regular word, "šleper" is 18-wheeler, verb "šlepati" - to tow, "šlepati se" - hang on (to someone/something) for the ride. I somehow think this one came straight from German - would be nice if any native German speaker could confirm that.
As for "schlemiel", it's probably the root of "šljampav" - sloppy, anti-neat.