Good idea: One of the featured products at the Demo conference in San Diego this week will be Moixa Energy's USBCELL, a AA NiMH rechargeable battery that takes a charge from any USB port. Pricing for a two-cell pack in the UK is £12.99, including free delivery and VAT tax. Availability outside the UK is coming soon, according to the company. Taking advantage of the billions of USB port and getting rid chargers and cables and wasted energy makes this technology very compelling. The company has 9 volt and phone battery versions in the works. The Web site doesn't contain any information on how battery life holds up over the long term.