Shop4tech offers this Mini DisplayPort to HDMI Adapter for $6.95. Coupon code "SUMMER" cuts it to $5.91. With free shipping, that's a buck under May's expired mention (which included a 6-foot HDMI cable) and the lowest total price we could find $6, aside from the deal below. It's compatible with most MacBooks equipped with a Mini DisplayPort. Deal ends June 19.

Of note, Easyi via Amazon offers Amazon Prime members this adapter for pennies less with free shipping.