I’ve heard that dual-booting Ubuntu linux was easy but its really true. I’m now running Ubuntu and it was as easy as various blog posts have said. The longest step in the process was defragmenting the drive before repartitioning with Ubuntu. There are a few issues remaining around using the data on the Windows partition from Linux, but on the whole I’m very happy with the switch.
[Update 1/29/2008: the network is inconsistent. Upon a boot or un-hibernate it may be completely incapable of finding my router - but then later it is fine. I'll continue trying to track it down... using the Windows OS!]