If you've got an iPhone, are a little bored with iOS, and you're interested in moonlighting with Google's Android operating system, you can dual boot Android and iOS side-by-side on your iPhone in a few relatively simple steps.
What You'll Need:
All you'll need to get started is an iOS device; Right now, the iPhone 3G has the best support, and that's what we're using in this guide.
Step One: Jailbreak Your iPhone
You've got a number of jailbreaking options, including PwnageTool, Redsn0w and Blackra1n. Pick one that works on your platform, download it and walk through the jailbreak process. (I'm not going to detail the jailbreak here since the latest jailbreaking methods often change a little.)
Step Two: Install Bootlace in Cydia
In order to do this, you'll need to launch Cydia from the homescreen, tap on the Manage button, select Sources, then tap Edit, then Add. The repository you'll need to add is repo.neonkoala.co.uk. Tap Add Source, let Cydia work its magic, and then tap on your newly added repository and install Bootlace.
Step Three: Run Bootlace and Patch the Kernel
Leave Cydia, and launch Bootlace. If Bootlace isn't on your homescreen after you leave Cydia, restart your iPhone and it should be there. Then just launch Bootlace, and let it download and patch the kernel. When it's done, tap on Reboot and wait for your phone to reboot.
Step Four: Install OpeniBoot
Now launch Bootlace again, tap the OpeniBoot button, and tap Install, then Continue. OpeniBoot will download and install.
Step Five: Install iDroid
Once OpeniBoot is installed, tap the iDroid button, tap Install, OK, and then wait. iDroid — which is essentially the Android OS customised for your iPhone — will download and install. This will take a while, so be patient, and if your battery is low, you may want to plug in your phone you start.
Step Six: Reboot and Play Around with Android
Now you've officially installed Android on your iPhone. Time to play around with it. Just tap on the QuickBoot button from inside Bootlace, tap the Android icon (the one of the little Android proudly holding an Apple), and confirm that you want to reboot into Android.
How Does It Work?
The first thing worth mentioning is that Android on iPhone isn't close to ready to use as your full-time mobile operating system. That doesn't mean it never will be, but at the moment, this is more something you'd want to do to fulfil your curiosity, wear as a geek badge, or just have a little fun and (maybe) support a really great project.
You can see how far they've come along with each phone on the iDroid status wiki. As I mentioned above, the iPhone 3G is the best supported iOS device (and currently only it and the 2G work with the method above, I believe). The biggest issue right now with the 3G is power management (PMU on the wiki), which isn't fully functional. Most importantly, suspend isn't yet working, so your battery won't likely last long. It's still come a long way from where it's been in the past, though, and having followed this project excitedly for a while, the progress they've made in recent weeks has been really impressive.
Regarding a few nuts and bolts: Your iPhone's lock button acts as the Android back button; the iPhone home button acts as the Android menu button; the iPhone's volume down button acts as the Android home button; and the iPhone's volume up button acts as... I'm not really sure what. To lock the screen, press the iPhone's home and and lock buttons at the same time. To power off, hold the lock and home buttons for a couple of seconds until the Power Off prompt appears. You can see a few other operating quirks by watching the video above.
As you can see in the video, performance isn't perfect (it's occasionally a little laggy), but again, with time, that could change significantly. Either way, the iDroid project — along with OpeniBoot and Bootlace — is something I remain extremely excited about. As a long-time iPhone user and recent Android switcher, the main thing that sets the two apart for me is the iPhone hardware, which always feels a head and shoulders above whatever Android device I put my hands on. I know a lot of people (including myself) who'd kill to dual boot an iPhone 4 with iOS and Android. (In fact, if you really want to help out, you can donate to the iDroid Project by clicking the Donate button on the top right of the iDroid Project's main page and maybe speed things along.)
If you've been playing around with Android on your iPhone, let's hear about it in the comments.