There's been a lot of talk about desktop modes i Android this week, but many don't realize that you can install an experimental build of Android on your laptop or desktop computer right now. Android-x86 is a derivative of open-source Android that runs on standard Intel-compliant hardware, i.e. the vast majority of computers out there. The latest modified version from Android-Dev.ro adds two important features: Ethernet networking support (for small computers like the Atom-based "net-tops" that lack WiFi) and virtualization, so that eager users can try out Android in Virtual Box, VMware or similar programs.
As always with virtualized software, the VirtualBox support is a little tricky: hardware acceleration is a no-go, and Ethernet only works in DHCP mode. On the plus side, it's running a full version of Ice Cream Sandwich, with new features like shared folders that can be accessed from the host machine and Android at the same time (not unlike plugging in a Honeycomb tablet with MTP file access). Otherwise it works just like the tablet interface you're (probably) familiar with, just with mouse/touchpad and keyboard.
To install Android-x86, you can download the ISO file and use it like an desktop OS disc. Burn it to a DVD, reboot your computer and get cracking, or just point Virtual Box to the volume. Fair warning, this is a pretty advanced way to try out Android, and having some previous Linux experience under your belt will help no end if things get hairy. The rest of us can just wait patiently for Android Jelly Bean or Ubuntu on Android.