My neighbors across the street don't have Internet access so I volunteered my WPA password to them so that they can use my Internet. Today I decided to install a custom WRT54G firmware called CoovaAP to turn my router into an open hotspot like you would see in hotels for my other neighbors to use.
It was very easy to install and configure. It uses CoovaChilli to create a captive portal to allow my neighbors create a user and log in. It also separates my hardwired network from the wireless hotspot.
I also installed ipp2p to block p2p traffic to keep the bandwidth usage down. Besides everyone uses p2p for piracy anyway (Don't try to deny it). Bittorrent is a great technology used for evil. Don't get me started on Limewire... Here's a howto on installing ipp2p on Coova