Like me, you might have bumped into the need for moving a lot of existing documents from a taxonomy structure into an OG structure.
Copy the following php code into a regular node (as admin) and it should allow you to choose which taxonomy term you want 'transferred' and which OG to 'transfer' it to.
The Taxonomy structure is not altered.
I'm NOT a skilled php or drupal developer - so look out! And all you Gurus out there: feel free to add and improve, but dont mock my spaghetti...