I just read this today on ismashiphone (link).. The posts describe the steps required to tether your iphone 3g(s) IF you are updated to the new 3.0 firmware. Since I use PDANet (paid for it too) I have not tried it personally, but I’m sure there are a few readers who love to have this capability.

I read through the post and the notes; so a few words of warning…

First off, like anything READ ALL THE STEPS!

• There is a fix if you lose Visual Voice Mail or SMS, so dont panic. look here. http://help.benm.at/help.php
• No one knows of ATT is charging or not for this service.  I’ve heard they are going to charge $50 a month (this site is saying $70) once they get their act together.  So I would use this sparingly until more is known. So far, I have heard of anyone’s bill going up.
• From what I’ve read, this should be reversable. You are only installing some software and updating settings.  Not sure though.

So there you go.  Give it a try and let me know if it works out for you.  As for me, I think I’ll stick with PDANet.