CodeWeavers brings Chromium to OS X and Linux
Although CrossOver Chromium works, please note that this is not intended to be used as a default browser. CodeWeaver's website even states that this is just "a proof of concept, for fun, and to showcase what Wine can do." This is important because at least on my MacBook running Leopard 10.5.5, CrossOver Chromium was extremely slow. Some images were also squished and text display was slightly off, probably a result of trying to compensate for Microsoft's ClearType and Apple's Quartz display engines.
To be honest, performance was significantly snappier running Chrome in a virtual machine in VMWare Fusion or Parallels than it was within CrossOver Chromium. But I suppose that's not really the point; the point is that the magic of Wine has made Google's latest browser accessible on Intel machines not running Windows. And that's pretty cool.
CrossOver Chromium is free. You can download it for OS X (10.4 or higher, Intel processor required) or in variants for Ubuntu and Debian (32-bit and 64-bit available), RedHat, Mandriva, Suse and other Linux distros here.