This piece (from Bloomberg Businessweek) makes some good points about the problems which a return to the drachma would cause for the Greek economy - including exporters. For example, the price of imported components and raw materials upon which many exports depend would soar. On the other hand, agriculture and tourism would benefit.
What stood out in the article for me was not so much the analysis as a reported remark by a disgruntled German guest (it would have to be a German, wouldn't it?) to an Athens hotel worker: "You don't have an economy, government, or money, but you're charging me €4 for a coffee."