Comment SL4A is great (Score 1) 783
I've been using the Scripting Layer for Android to code a small python app. It uses the voice recognition and speech synthesizer to do do things like read the weather for me, and connect via socket to my home computer where I have a server running to execute some commands like playing music and such.
It work great! The entire python standard library is included and some things like Twister works as well.
The Android API is not entirely fully fledged, but I've been able to access all functions I want (sensors, speech, build menus among other things). If you need full control and access to all API-functions though, java is the only way to go.
I could't imagine why you would want to use BASIC instead of Python. If for some reason you dislike Python, you've got Ruby, Perl, Shell and more.