One of them is up at Cloth Diaper Addiction for a Bumkins cover from Natural Pure Essentials. Honestly, even if you don't want to go follow CDA's blog or enter the giveaway, definitely go read the review. It's a neat little cover that has a lot of features, including a venting component to promote airflow.
You can read the review here:
While you're there, take a look at the Bummis Polar Fleece cover review and giveaway as well.