[Motorola Atrix 2] br0adband:
Best solution:

1) Get Ubuntu ISO (desktop i386 is fine, there's no requirement to get the AMD64/x64 version, none whatsoever, and there are always some issues with x64 versions - people will say there aren't but, after dealing with Linux since it first came out and Slackware 1.0 nearly 20+ years ago, I'm not kidding). Best source for the torrent (and fast to download) is here:

http://mirror.anl.gov/pub/ubuntu-iso/CDs-Ubuntu/precise/ubuntu-12.04-desktop-i386.iso

2) Get Wubi from here:

http://www.ubuntu.com/download/desktop/windows-installer

Wubi is a tiny Windows executable that allows you to "install" Ubuntu into a folder - literally the full entire OS is installed inside a folder (it'll be \Ubuntu in the root directory unless you choose a different location with the installer). The purpose of Wubi is to allow you to "install" Ubuntu without mucking up your system:

Note: the Wubi.exe file is also included inside the Ubuntu 12.04 ISO but some people either aren't aware of it or don't know how to extract a file from an ISO (WinRAR can "read" ISO files just fine if you use it). I gave the direct link to Wubi for download because on occasion it is updated and could fix a bug or whatever that was in the original version included on the distribution media, aka the ISO. Ubuntu 12.04 came out in April so it's been out awhile now, best course of action is get the direct download version of Wubi from the link I provided.

What it does by installing into a single folder is allowing you to continue using Windows as you want, and if you get the urge to do some Ubuntu work, you reboot the PC, choose Ubuntu in the boot menu (it does not install GRUB into the Windows bootloader, it just adds an entry to point to the folder where Ubuntu is which has a chainloader GRUB bootloader which THEN kicks in - your Windows bootloader is never altered or changed in any way).

You then "boot" into Ubuntu, do all the necessary setup since it's the first boot, set up the user account/password, etc, and it'll reboot of course when the updates are installed and you choose Ubuntu again, etc. Or back in to Windows, it's your choice.

Now, the beauty of all this is simple: it doesn't require partitioning the hard drive since you're installing into a single folder. Wubi does ask you for the size of the installation, and depending on the free space you have it'll make a suggestion, but a full complete installation of Ubuntu 12.04 will be about 4.8GB after all the updates and patches are installed, so if you choose something like 12GB for the installation size, you'll be fine for a very long time to come. You could install every Linux dev tool there is, every compiler, IDE, etc, and you'd still have gigs to spare. :)

Anywho, the final grand aspect of this is that if you get sick of Ubuntu, decide it's not for you, or you just flat out give up on it (you probably won't given your posts so far), you can run the Wubi installer once more from inside Windows (obviously), and click Uninstall and wham, in about 3 seconds, Ubuntu is gone, completely, with no trace of it aside from the Wubi installer and the Ubuntu ISO if you keep it around.

That's it. That's the simplest way to use Ubuntu on a PC - this is a better method in the long run that using a VM because you're not dealing with a HAL (Hardware Abstraction Layer) and you get direct "bare bones bare metal" work on Linux/Ubuntu.

If you choose to take the Virtual Machine route, VirtualBox is the recommended VM app. VMWare Workstation or Player is nice also but hugely bloated stuff, and they both leave 5 services running in the background even when the main application isn't running - VirtualBox is clean, has nothing running when it's not, and is very lean and mean on resources. Takes longer to get set up than using Wubi but, the primary benefit with using a virtual machine is you run both OSes at the same time, no rebooting to one or the other is necessary.

And VirtualBox has excellent USB support nowadays (USB 2.0 also) so it's entirely possible to do all your learning and experimentation with Ubuntu in VirtualBox and get things done just as easily without having to dual boot.

Hope this helps, but if you need more info just ask, someone will cough up the info. ;)