Halo 3: Where's mah skulls?

So, by now we're betting that most of our readers have finished most, if not all, of the Halo 3 campaign. From here there are several natural progressions. Maybe you'll start fiddling around with the saved film feature, taking screenshots of your most glorious moments. Perhaps you'll delve headlong into multiplayer, owning n00bs and taking names. Then again, you might try your hand at creating the perfect maps and game types in Forge. But, if you're like us, part of your post-campaign regimen will include the search for skulls. For example, we just took an ill-advised blogging break to grab the elusive IWHBYD skull with a Joystiq buddy. The fever even seems to have gripped the folks at Penny Arcade, as you can see from the image at right.

We'll admit it, we're using guides, guides, guides. Off the internet of course -- we're not going to do something silly like pay for one. How goes your hunt for the skulls? Are you employing the mass-intelligence of the internet or are you going it solo, trusting your killer instincts to uncover them? Dare we ask if there's anyone out there with all of them?