For those who have a Chase credit card and can log into a Chase account, refer to this post for a $125 bonus.
You may also be able to get a $125 coupon from your local post office. Please refer to this post for more details and for issues related to Chase, this checking account and these promotions.
Don't forget you can stack this new account bonus with a $25 refer-a-friend bonus.
Bank of America Checking Account Bonus
Bank of America used to have a $100 bonus for opening a new checking account, but this has recently gone down to $75. They continue to update their promotion page. The current $75 offer requires that the account be opened before April 30, 2008. The offer code is AOU260208. For more details about this promotion and the MyAccess Checking account, please refer to this post.
Note, these bonuses typically require that you are a new checking account customer.