Wired Connection + Internet Connection Sharing + OpenVPN?

[Todd]

If you have a 3G connection your Internet is neither free and unless your 3G carrier is giving you unlimited Internet w/ no cap you don't have that either. The VPN still uses data over the 3G connection , therefore uses an Internet connection (and uses more as each packet probably has 10-20 bytes of overhead added). All a VPN does in encrypt your data.

Is your laptop running DHCP server on the wired side? Also check your firewall settings. I believe your assumption about the PS3 traffic not using the tunnel is correct. The VPN client is meant to send data from the clients machine to the endpoint, but not other traffic. Check and see if there is a setting in the VPN client to send all data through the tunnel.

I'm not sure what "hack" you are referring to, as you haven't described anything that wouldn't be technically feasible using readily available technology (routing traffic to a VPN tunnel).