I got a letter from CitiBank with an offer for 20,000 ThankYou Points (worth up to $200) for opening a checking account. It seems better than other deals I've seen recently, but there are requirements. It may only be valid for Citi credit cardholders who got this letter.

The short version:
Go to offer.citibank.com and enter code CE2T, or call 866-445-8706 and give them that code
Open a regular checking account (AKA The Citibank Account) with minimum of $1,000 by 6/30/09, and enroll it in ThankYou Network
For each of the first 3 months, have either 1) a direct deposit; 2) 2 electronic bill payments; or 3) 5 non-PIN debit card purchase transactions, and you get 10,000 TYP
If you do that again for each of the next 3 months, you get another 10,000 TYP
The Citibank Account requires a combined balance (checking, savings, money market, retirement, credit card balances, loans, mortgages, etc.) of $6,000 or more to avoid monthly fees; having a $6k credit limit on a credit card does not count

The fine print:
This offer is available to Citi cardmembers who receive this communication. Offer is not valid for existing Citibank checking customers. All accounts subject to approval and applicable terms and fees. Persons under 18 years of age are not eligible. Offer may be modified or withdrawn at any time without notice, is not transferable and cannot be combined with any other offer. Separate enrollment of eligible checking account in ThankYou network required. ThankYou Network enrollment and participation are subject to terms, conditions and restrictions. Participation limited to United States ("U.S.") citizens or resident aliens with a valid U.S. taxpayer identification number. Customer is responsible for taxes, if any. Monthly points for checking account relationship require customer to initiate minimum of one credit or debit to the account per statement cycle. Customer must deposit a minimum of $1,000 into checking account opened in a Citibank Account, Citibank Everything Counts or Citigold account relationship package by 6/30/09. Within the first month after account opening, customer must complete at least one direct deposit to, or at least two electronic bill payments from, the checking account, or five or more qualifying non-PIN purchase transactions using your Citibank debit card each month for three consecutive months to get 10,000 ThankYou Points. Customer must continue to make a direct deposit or two electronic bill payments, or five or more qualifying non-PIN purchase transactions using your Citibank debit card each month for an additional three consecutive months to get an additional 10,000 ThankYou Points. Electronic bill payments are those you make using Citibank Online, Citi Mobile or CitiPhone Banking. A bill that is paid by making a transfer between linked accounts does not qualify as a bill payment for this offer. Qualifying purchases must be submitted through the MasterCard Network and are those for which either you or a merchant designates as a "credit" transaction (including purchases you sign for, small dollar purchases that do not require a signature and use of your MasterCard PayPass), Internet, phone and mail-order transactions. Qualifying purchases do not include those initiated using a Personal Identification Number (PIN) or other transactions submitted through other payment processing networks. Each award of 10,000 bonus ThankYou Points will be credited to your ThankYou Member Account within 120 days from the end of the statement period in which you met qualifying requirements stated in this offer. Your Citibank checking account and Citi credit card account must be open and in good standing at the time the bonus ThankYou Points are posted to your ThankYou Member Account.