Yes, it's a bit too late for Europe now, but moving forward this could be a useful bit of financial innovation.
Greece and Ireland need to depreciate their currencies, but exiting the Euro is unworkable for either of them. Extraordinary times call for extraordinary measures, so they could both temporarily introduce import tariffs for EU products, as well as potentially recycle some of the money generated to export tariffs.
Imports go down, exports go up, GDP increases, deficit goes down. Of course this doesn't work in the long-run the way depreciation would, but it would work a treat as a short-run stimulus and deficit-reducing measure.