A few years ago I was at a cafe in a venue that had a large conference/gathering, and their router was handing out 24 hour DHCP leases and ran out of IP address

A few years ago I was at a cafe in a venue that had a large conference/gathering, and their router was handing out 24 hour DHCP leases and ran out of IP addresses. It was a fairly technical group so me and a couple other people set up a table with RFC 2322-style pieces of paper with IP/gateway info ("please return when finished") and it worked surprisingly well!