OLPC have restarted their Give One, Get One scheme, which allows buyers to purchase an XO laptop for themselves while at the same time donating one to a child in the developing world. In fact, two options are available: $199 simply donates an XO, while the full scheme is $399. OLPC have partnered with Amazon to process the orders; in the US, XO laptops will begin shipping in 30 days.
Outside of the US, the Amazon UK site will be handling all orders. Deliveries are expected to begin in Q1 2009, or perhaps later. The machines in question will be running Linux, rather than the Windows XP build specially customized for the XO's hardware. Interestingly, several companies - Google and SWIFT being two examples - are pledging to meet and double their employees' donations.
Over 100,000 XO notebooks were donated to developing countries when the Give One, Get One scheme ran last year. Apparently more buyers chose to donate than to buy for themselves. The US site is http://www.amazon.com/xo while the site for purchases outside of the US is http://www.amazon.co.uk/xo; however, at time of writing it does not appear to be live.