Today, the Jolicloud pre-beta has been released and it's ready for the general public to install on their Windows netbooks.
Jolicloud's Wubi-derived installer make the process dead-simple. Download the 600Mb .exe [or the torrent] from their website, launch it, and make your selections. Within a few moments you're system can dual-boot into Jolicloud or Windows.
While I suppose it's technically not fair to compare Jolicloud and Chrome OS right now since Chrome is so early in the alpha stage, I'm going to anyway. Right now - and for the near future - Jolicloud is the winner in my mind because it supports both native and web-based applications equally well.
"Sure, but Jolicloud uses Firefox and Firefox is slooooooooooow!" you say? Fine, go grab the Google Chrome beta for Linux and install the 32-bit .deb on Jolicloud. There. You've got a nice, fast, webkit-based browser - just click in from your internet apps tab.