<p>The title should say it all, then I can solidify 2 more ticks on the Joel test. </p>

<p>I've implemented build automation using a makefile and a python script already and I understand the basics and the options. </p>

<p>But how can I, the new guy who reads the blogs, convince my cohort of its inherent efficacy?</p>

Ask for forgiveness, instead of permission.
Get it working in private (which it looks like you have) and then demonstrate its advantages.
One thing that always gets people is using CruiseControl's Tray utility - people love it when they can see, through their system tray, that the build succeeded. (this is assuming you're in a Windows environment, that CruiseControl will work with your existing systems, etc.)
NOTE: If asking for forgiveness instead of permission will result in instant termination, you might not want to do the above. You might also want to look for work somewhere else. Your mileage may vary.