This deal has ended.
Newegg drops the price of this Energizer Protective Case w/ Built-in Battery for the iPhone from $79.99 to $14.99 with free shipping. This case protects your iPhone from damage but also has the added benefit of extending its battery life by approximately 4 hours of talk time or 20 hours of music playback. On 135 reviews it has 4-stars, so it is a quality product. There is no sales tax (except CA, NJ, TN).