Android is quiet famous mobile operating system, yet many had tried to run the same on desktop system. There are number of things that create a issue here. Androidx86 looks like the only one trying to port Android on x86 platform. There are number of emulators which had been failed to give a better option. I had tested Bluestack on windows some time ago, but that makes the system too slow. To some extent on Linux platform it is possible to run a apk file. For that you have to find the right emulator. If you are willing to run games or test application then this is one of the best option you can go for. I had tried to accumulate all things that is possible. You can port the operating system on Ubuntu desktop and then install app also on the same. The reason why we cannot manually modify Android OS content, is that your operating system is not able to read the file format. I had created a bootable ICS pen drive some time ago. It worked quiet well, but I was not able to connect on web, nor able to run apk files. There are many more limitation for android to support desktop system. But in future we can hope for a edition that come for pc as well as for mobile phone. What matter is porting the right key settings. Android is still flourishing. I had found some number of ways by which you can run Android on your Ubunut desktop.
Method 1 --- Using AVD Manager
Ubuntu have certain amount of packages that you can test out to run Android on virtual host. To run that you have to download certain files. the first one is openjdk and the second one is ia32-libs library. That last package that you have to download and run is Android SDK for Linux. You can find this packages in Software Manager. Just type the name of packages that I had mentioned. You can also download Android SDK from internet. The download size will be minimum. Now when you are done with the download ensure that openjdk is installed. Then Android SDK. You will see a screen of Android SDK and AVD Manager. Now go in Settings and choose Force https:// sources option. Click on Save. One you are done with that you have to click on the second option Installed Packages. Install everything. Then go on Virtual Devices and click on New. You will see a popup window which will show you option to Create New AVD. Add up information as per needed. Once it is created properly you will see a android emulator. You can use this emulator to install and use android apps. The keys are provided on the screen that you can operate from your mouse.
Method 2 -- Oracle VM VirtualBox
Virtual Box is another option to test android apps. For that you have to download and install Oracle VM VirtualBox and Android-v4.vbox. The process is very simple here. But this is a bit buggy. There can be issue related to compatibility. When you are done with the installation of virtual box simply download ICS for VirtualBox. You have to load the operating system in Virtual Machine. This is the only complex part here. Click on Start so that you can see Grub loader. Choose the operating system and then done. You can see Android working inside Virtualbox. You have to first find the right VirtualBox version for your system. Because if it is not compatible with your existing system, then you can face a buggy issue. You can then run Android inside that and operate it with your mouse keyboard. This is one of the best way, as there is no need to worry about dual boot stuff. It works nicely and has better ouptut. For testing purpose I recommend you to test android virtualbox.
Method 3 - Via Bootable USB Drive
You can download Android from Androidx86 and create a bootable drive using Unetbootin. You can use this tool to create a bootable usb drive. You can then run Android from the usb itself without touching any existing operating system settings. This is another safe method of testing android on desktop. There are certain limitations here. First when you use usb as the bootable media, you might not be able to use internet on it. Second if anyhow you manage, you cannot open Google Play as the operating system entirely depends on network sim settings. But still it is fun to test. There are certain limitation of keyboard and mouse usage. It is complicated to handle a number of process. I had checked a ultraportable laptop that comes with Gingerbread. It was quiet nicely modified to work with Intel Atom. Using Andorid on desktop always keeps certain limitations. There can be limitation to app setup or somehow limitation to internet configuration. While other all stuff work quiet well.