Today only, DealsClick offers the XtremeMac InCharge Mobile Rechargeable Battery Pack for iPhone 3G / 3GS, model no. IPP-MPK-11, for $2.99. With $4.99 for shipping, that's $4 under our spring mention and the lowest total price we could find by $5. This battery pack purports to extend the iPhone's talk time by up to four hours and includes a mini USB-to-USB cable for charging and syncing.