I just installed Ubuntu 12.04 LTS "Precise Pangolin" on my BeagleBoard xM. The installation was just flawless (and I mean it: flawless). After a few minutes, in the first boot, I am now composing this page online using Firefox browser (and a number of open tabs) while in background I have a number of other windows and tasks. Installing Ubuntu was never that simple.
Yes, it is not as snappier as my gorgeous multigigahertz-multigigabytes notebook (this is also due to the class 4 microSD card I popped in) but is somewhat usable.
First, I fetched on cdimage.ubuntu.com/releases/ the "omap" image (not "omap4") and uncompressed it on an 8Gb microSD card (a 4Gb one will leave some 2Gb free space; I just happened to have a spare 8Gb one).
Then I attached my Samsung 21" 1440x900 display on the DVI port, the ethernet cable going to my Internet connection, and a Logitech wireless keyboard+mouse combo. Then I attached the 5V cable and in a few seconds... ecco qua! the Ubuntu booting display:
I am now upgrading/installing some stuff (duh, 930Mb download ongoing... LyX and QT4 are quite heavy) while writing this page. Wonderful. An Ubuntu machine sporting Firefox and the usual stuff... totally silent and with absolutely no moving parts.