The FCC is now providing public wireless access. There is no login or registration information required:

The system uses the 802.11a and 802.11b protocols, commonly referred to as WiFi. The Commission will be unable to provide technical support, and all transactions using this service are the responsibility of the visitor. At present, the FCC will not request personal identifying information prior to allowing access to the wireless network. If requested by outside authorities, however, the FCC will provide data from system audit logs to support external investigations of improper Internet use.

...via BoingBoing