2 amps? Sounds a bit optimistic. My Gigabyte motherboard is actually able to "overdrive" the USB port with up to 750mA to supply the fruity i-Devices with charging juice. However, I don't know of any motherboard out there that would output 2 amps on a single USB 2.0 connector. Yes, it's a 2.5mm power plug. If you have some old Nokia cellphone power supply from a phone that's no longer in use / already dead; they had the same connector for quite a while. Clip off the cable right at the charger and re-use it. Yes, it's intentional by design, and there's no easy "let's patch a wire from the USB +5V pin over to the charging jack" solution either as the tablet is actually outputting +5V on the µUSB for USB OTG connected devices (Mice, Keyboards, 3G mobile sticks, ...). I wish you luck in your quest to set your inner MacGyver free.