The folks behind Mandriva Linux already added support for the Eee PC 700/701 series to their 2008.1 release which was released in April. That means you can install Mandriva on an Eee PC from a CD or from a flash drive and it will work out of the box, no modifications necessary. That means the Fn keys, the WiFi, and the graphics should all just work.
But if you have an Eee PC 900, you’ll need to tweak things a bit by upgrading your kernel and hal-info packages. But it turns out there’s another option: You can purchase the Mandriva Flash 2008 Spring edition for 59 Euros or about $91. This version comes on an 8GB USB flash disk and includes all the updates you need to get Mandriva 2008.1 up and running on an Eee PC 900.