In case you're interested, I managed to get ROS running on Ubuntu on
Android on my phone (a Motorola Droid Bionic).  I'm not sure how useful
this would be to anyone, but it's kind of neat.

I did have some build errors when "Building the higher-level/tools (Layer
2)", but roscore, turtlesim, rxconsole, rxgraph, and rxplot work.

An overview of the steps:
 - Rooted my phone.
 - Install the Terminal Emulator program from the Google Play app store.
 - Downloaded "Complete Linux Installer" from the Google Play app store.
 - Used that to download and install Ubuntu (large version).
 - Followed the guide in the Complete Linux Installer (unziped the image,
and moved it)
 - I had to make the .img file bigger because there was not enough space
for ROS (in the terminal, outside of Ubuntu: cd /mnt/sdcard/ubuntu; dd
if=/dev/zero bs=1M count=1000000 >> ubuntu.img)
 - Followed the instructions on the ROS Debian install page.
 - Had to change a couple of lines in turtle.cpp to get it to compile
(needed to typecast a constant to qword in the std::max function call)
 - As per
http://answers.ros.org/question/36890/unable-to-find-swigswg-and-unable-to-find-pythonswg/,
had to cp -r /swig /usr/local/share.

It's slow, but it seems to be faster than the Rasperry Pi.

Screenshot: screenshot<https://lh6.googleusercontent.com/-A2nk374OW2k/UHf7lv2AxuI/AAAAAAAAClo/JQX-yI5v1Fg/s455/ROS_phone.png>

-Jon