Short answer: You can't.
@Backslash17: Looking through the article and the following link with installation instructions, all the company got working is to launch a self compiled executable on the emulator, bypassing the android framework. Once you have the emulator you can telnet in and have a linux shell. Running a linux program there is trivial of course.
But that's not working for phones without jailbreak(aka root access) and not deliverable on the market.
Unless Google opens other opportunities or someone writes a custom compiler that compiles Language X into Dalvik bytecode (Dalvik is the VM that runs Android programs) you won't be able to write native code.