As you might know already Ubuntu is building for the ARMv7 architecture.
As an owner of an OMAP35x EVM board i have put some time into getting a usable development image together that can easily be installed onto a SD/SDHC card and be used on that board for Ubuntu development.
http://people.ubuntu.com/~ogra/arm/OMAP35x_EVM/ has the necessary instructions and links to get up an Ubuntu development system on your OMAP35x_EVM board, if you own such a device and want to help us with ubuntu development, now is the time to start getting involved !!!
If you have any questions about Ubuntu on ARM, feel free to drop by in #ubuntu-arm on irc.freenode.net at any time or use the ubuntu-devel and ubuntu-devel-discuss mailing lists on lists.ubuntu.com