https://poloniex.com/dao/To acquire DAO tokens, you can use this page to transfer Ethereum from your Poloniex account to the DAO smart contract. This will appear as an ETH withdrawal in your transaction history. Poloniex will not be charging a network fee for these transactions.
And for poloniex the exchange address is:
0xe165c74659a13cbb9c379742f293622c761d528d
I was getting an error with the DAO exchange page so the admin sent me the address. My rate came back from the rate prior though, not gonna complain

May pick up more for that price, i see a large demand for the tokens as it opens trade.