Well, I thought I would post a tutorial on how I got Lenny working on my Eee, incase people are having problems. This will loosely be based on the Debian EeePC wiki and also this blog post: http://demenzia.net/2008/02/22/using-suspend-to-disk-with-eeexubuntu-on-... so this content is not 100% from me, only what worked. Just for a note, my EeePC is a 701 4GB (with camera)
Firstly, download the EeePC installer image here: http://eeepc.debian.net/debian/images/debian-eeepc.img
You will need a USB flash drive, but I'm sure a SD card will work. Now to copy the image onto your media choice:
dd if=debian-eeepc.img of=/dev/#YOUR DEVICE#
sync