RE: Wireless Network Question

If you forced your customers use 802.1X for authentication they wouldn't get
an IP address unless they were authorized.

If 802.1X is not in the mix, another solution is to give them a very short
lease (say 2 minutes) until they've completed web-based authentication, and
then give them the one-hour lease. Any portal-based product for wireless
hotspots can help you out here.