Need to keep shakin' it all night long? The UK laptop company Rock has the laptop for you: their pegasus t12 has a high capacity battery that they claim will run for up to 7 hours. The big battery holds 10,000mAh of charge; most laptop batteries hold around 5000. Prices start at 649.00 (around $1230) for a system built around a power-sipping Celeron processor with a 15.4-inch WXGA screen.
Rock's 'All-Day-Battery' Core 2 Duo Laptop [BIOS Magazine]
Pegasus t12 [Rockdirect]