San Diego Metropolitan Credit Union has a very attractive certificate promotion. The promotion includes a 4.25% APY 12-month CD and a 4.00% APY 6-month CD. You can earn an extra 0.25% if you currently have or if you open a qualifying checking account. Minimum deposit is $10,000, and these are also available as IRA certificates. This promotion is listed at the credit union's front page and in this promotion page as of 12/28/08.
Membership is open to all those who live or work in San Diego County, California. Please refer to the credit union's membership page for the full details regarding membership eligibility. Membership requires a minimum balance of $10 in the regular savings account.
The credit union is federally insured by the NCUA (Charter # 61003).
Thanks to the reader Bob who mentioned this promotion in the comments.