Since we're on the topic of backyard effects with that Russian Transformers clip, let's take a look at the technique of integrating 3D objects with live action footage. The technique of placing a 3D object into a previously filmed scene (known as matchmoving) requires sophisticated camera tracking generally reserved for high-end effects packages, but Aetuts+ has a tutorial for doing it with a free After Effects plugin called Voodoo Camera Tracker. I've only done 2D tracking myself (to erase people and other background elements in The West Side), but if you're interested in integrating your own 3D transformers (or something more original, perhaps?) into a live scene, here's a tutorial for you:
Matchmoving has been discussed a lot these days and it has become accessible for more and more people. With the introduction of programs like Syntheyes, PFTrack, and The Foundry’s CameraTracker plug-in the reconstructing of a 3D camera move has been made easier. A lot of people however are not aware of other solutions that are available, like free software. Voodoo Camera Tracker is one of those pieces of software and today I´ll be showing you how to solve your shot and then create some awesome 3D stuff within After Effects!
Here's their video example -- it has some glitches, but hey, you get what you pay for:
Note that Voodoo Camera Tracker is Windows and Linux-only.