Apparently the promo code is still (sort of?) active. Just go to this URL:
http://www.buy.com/retail/coupon.asp?prid=82865916
Click the Redeem Now button, then look up the SKU listed, it will point you to the Pogoplug. Add that item to the cart, and it should show as $44.99. NOTE: This ends at midnight on 8/2.
The E02 is also on sale, no coupon code, for $39.99
http://www.buy.com/pr/product.aspx?sku=213816247