If this is tested and works fine on 1.5 I can add you on project on joomlacode to add the files there.

Can you give me your joomlacode username?

Thanks. I added you as project admin to:
http://joomlacode.org/gf/project/vodes/

I created a new package called Vodes_Joomla_1.5:
http://joomlacode.org/gf/project/vodes/frs/admin/
please add your files there.

Thank you.

Great! Thank you.

Ideally you can keep the file any where you wish. Just make sure the file(f) using Vodes class includes this file.
I prefer to keep the vodes_util.php in the same directory as the file using it(f). Then you may write
require_once('vodes_util.php');
to include the file and can use as you wish.

I guess this is a stupid question but where does the vodes_util.php file go?