iEGrow via Amazon offers its iEGrow Portable USB Mini Fan in several colors (Black pictured) for $13.99. Coupon code "ZFSPEWWB" drops it to $9.79. Plus, Prime members bag free shipping. Excluding the below mention, that's the lowest price we could find today by a buck, although we saw it for $1 less two weeks ago. This foldable fan features adjustable speeds, an umbrella hook, metal clip, and rechargeable Li-ion battery with up to 11 hours of run-time per charge (on lowest speed). Deal ends June 21.
Don't mind waiting for your deal? Superlight360 via eBay offers it in Green for $7.99 with free shipping. (It's available in several more colors for $8.30.) However, this item ships from Hong Kong and requires three to eight weeks for delivery.