We heard a banana explodes in a microwave so we decided to try it. I used a banana that was beginning to brown and I think it had a different result than a "green" banana. It didn't explode, but it was still pretty awesome. Watch!
I have an aunt who still walks by the microwave 'quickly' if it's running! So here's the official answer on whether it's ok to stand in front of a running microwave.....(and yes, some radiation does escape!)