So what I have here is nothing fancy. It's basically cut and paste from the Chromium site, but if you don't want to think, just download and run, and have Chromium on your Ubuntu setup.
So, on with the script:
The comments speak for themselves. Basically, get prerequisites, get tools, get source, build away. This process will take awhile, so once it starts go flirt with your significant other for a bit :)
So to get up and running, just download the script (click the 'view raw' up above), make it executable, and run it!