Update 11/22/08: The top yield has fallen to 3.82% APY. See bottom of the post for the rate history.
The State Bank has a reward checking account that pays 3.82% APY on balances up to $25,000 (1.01% for above) and refunds ATM fees (up to $25 per cycle) if the following monthly requirements are met: 1) 12 debit card signature transactions, 2) one direct deposit or ACH auto debit, and 3) receive electronic statements. If these are not met, the rate falls to 0.20%. The checking account is free with free online bill pay even if the requirements are not met.
It's a small bank with a very basic website, so I would guess they require a branch visit to open accounts. Branches are located in the Colorado cities of La Junta, Rocky Ford and Peyton. The bank has been FDIC insured since 1934 (FDIC Certificate # 1778).
For other high yield reward checking accounts and to learn more about these accounts, please refer to my High Yield Checking website.
11/22/08: 3.82% APY
04/22/08: 5.10% APY (initial post)
Edit 2/10/09: Added signature requirement to debit card transaction as opposed to PIN