We’ve covered creating a hackintosh PC and putting OS X on the Asus Eee before. Making OS X work on a PC usually involves downloading a patched version of the OS X installer and running a patched kernel. It works, but the potential exists that you’ll run into problems with Software Update.
This hack is a bit different. Instead of hacking the kernel, you use a bootloader called BOOT-132. It basically runs before anything else starts up and, with a few kernel extensions, it makes the system resemble the boot process of a stock Mac to the retail, unmodified Apple kernel. This means you can install OS X on your Eee with the Leopard disks you own, without modification, and without downloading a big ISO off bittorrent. It also means you can run Software Update without worry, since you are using a legit, unmodified OS X kernel.
EEEMac Journey has the full step-by-step instructions for making this all work. You have to boot off of the boot-132 CD a few times during the install process, but once you’re done, the machine will be set up to boot straight from the internal disk. I’m not sure if it’ll work, but there’s a good chance this process will work with other netbooks and Intel-based PCs with supported hardware.