There are a lot of software engineers with too much time on their hands. First (in 1990) there was “RFC1149”:http://www.ietf.org/rfc/rfc1149.txt – ‘A Standard for the Transmission of IP Datagrams on Avian Carriers’. Then there was “RFC2549”:http://www.ietf.org/rfc/rfc2549.txt which added quality of service to the protocol. Two years later in Norway it was “tested for the first time”:http://news.com.com/2100-1001-257064.html but took an hour and 42 minutes to transfer a 64-byte packet of information. Finally, in March 2004, by strapping 4Gb of memory cards to each pigeon, researchers managed to transfer data 100 Km using Wi-Fly – pigeon-empowered wireless internet and managed to achieve effective speeds of 2.27 Mbps.
Personally I would rather receive my email in a barrel strapped to a St Bernard dog…