Yes, it's absolutely, positively true! I thought the day would never come, but it did! A hacker by the name of planetbeing has posted a video on YouTube of what appears to be either Android 1.5 or 1.6 running on the iPhone. Before anyone says, "This looks shopped!" or "Fake!", read his blog post about this first, then watch the video of it in action (linked below).
According to planetbeing, this is an iPhone 2G that's running Android, but it's likely that it may be relatively simple to port to the iPhone 3G as well. The iPhone 3GS may need some extra work.
But enough yap... this is utterly amazing to see! The iPhone is finally running true alternate OSes, which is something I've been wanting to see since it first arrived on the scene in 2007. If I did have a disposable income, I'd buy an iPhone 2G or 3G just to try this out, or help planetbeing test and develop further. Perhaps at one point or another, Android 2.x may be a reality! :-)
Check out the article on Android Police here, and don't forget to pay a visit to planetbeing's blog (linked above)!