XO upgrade kit turns an XO-1 Laptop into an XO-1.75. The XO Laptop is a small, cheap, durable laptop designed for use in educational settings — even in locations that have little to no reliable access to electricity.
The OLPC is offering a kit that will upgrade a XO-1 or XO-1.5 laptop into an XO-1.75. This upgrade will involving swapping out the existing motherboard which would either be the first gen XO1 which had a 433 MHz AMD Geode x86 CPU, 256MB of RAM, and 1GB storage. Or the later generation XO1.5 which had 1GHz VIA C7 x86 CPU, 1GB of RAM, and 4GB of flash storage. Once the motherboard has been upgraded you would essentially end up with a laptop equivalent in specification to the XO-1.75 which would give you a 1 GHz Marvell ARMADA 610 ARM CPU, 8GB of internal storage and 2GB of memory.
The One laptop per child range of XO Laptops are cheap mini laptops running a Linux distro called Sugar OS and are primarily made for using in educational environments. They have durable dust resistant cases and screens.
You can find more information about ordering upgrade kits at the OLPC website.