On the first full weekend of every month, Bank of America and Merrill Lynch offer their cardholders admission to over 150 museums for free during its Museums on Us promotion. There are museums participating in 32 states and you can find a complete list here. (California is a best bet, with 21 participating museums across 12 cities; and New York/New Jersey has a high concentration also.) A photo ID and Bank of America credit card, ATM card, or Check Card must be presented.