I've spent a couple of days trying and failing over the weekend to build an Ubuntu 12.04 VM which was able to build and run Android apps using the Titanium Appcelerator IDE. The requirements are very confusing and the whole system is quite fragile. At home I was working with a 64-bit VM, but I've now given up on that idea because ia32-libs seems to be required and that's no longer provided by Ubuntu. I've now built a 32-bit VM, and after much hassle I've got things building for Android and running on the Android emulator. The basic rules:

• Add the webupd8team ppa to the repos and install the java 6 jdk. Don't install any other javas.
• Install build-essential, dkms, libjpeg62 and libwebkitgtk-1.0-0
• Download and unwrap the latest nodejs package, ./configure, make and sudo make install.
• Create .npmrc in your home directory with this in it: prefix=/home/mholmes
• Make sure this is in your .profile: $PATH="$HOME/bin;$PATH" (and make sure $HOME/bin is there).
• Make sure $HOME/tmp is chowned to you and writable.
• Download and install the Android APK bundle and put it in your home directory. You can then point Titanium at it later.
• Download and unwrap Titanium in your home folder.

When you first run Titanium, let it do the updates it identifies; then restart it to confirm that it succeeded and doesn't ask you again (several times I've been caught in a loop where it installs, but thinks it hasn't, so tries again every time you start it up). Then install the platform SDKs. I succeeded in installing Android and Tizen, but Blackberry keeps failing.