Bitomat is the first Polish exchange offering PLN support.
Traders upload funds (PLN or BTC) to the site and then place orders to buy and sell. Bitomat acts as an escrow.
Funds are credited after each transaction immediately to accounts wherein they can be withdrawn off-site.
Usually it takes just a few minutes to transfer PLN from/to bank account (as long as its mBank bank account).
The exchange went online on April 4, 2011.