I did a search but couldn't find anything...

Below is the email from iFrogz. Here are some things to keep in mind: First, make sure to pick a free screenz wheel cover with each case. It adds $3 but it comes off in the cart. Also, you can get two of them, and shipping will be $8. If you get one, shipping is $5.99. That's $4 a case less FatCash if you buy two, a pretty good deal. These cases have speakers built in. Don't expect world class sound, but they're apparently pretty neat. You can choose from regular or treadz version. Unlike in the past, you can't combine coupons, so you can only use "free4me" in your cart. That's it. Hope some of you can get a nice case with this deal.

Link - the audiowrapz are in the middle of row 1 (regular) and the first one in row 2 (treadz):
Audiowrapz

"That's right! For a limited time, get a FREE Audiowrapz set (with Screenz) for iPod Nano!

We want you to spread the word to your friends and family about the award winning Audiowrapz Speaker Case, —the first and only speaker case for the 3G Nano.

More than just a case, Audiowrapz, by iFrogz offers the best in protection, style, and sound.

This 100% silicone case utilizes a unique passive speaker technology that does not require batteries!

Listen to your iPod Nano with or without headphones!

Just enter coupon code "free4me" at checkout to get your FREE Audiowrapz case (limit 2 per customer)*

Quantities are limited so act fast!

Also check out our new EarPollution Toxix headphones and Plugz ear-buds.

Thanks!
The iFrogz Team"