The problem for most is either cost (a 64M USB flash drive via USB host) or power (wifi hard drive case). 16G will hold several hours of (iPod compressed) video. I have a Cradlepoint PHS (battery powered wifi AP) with EVDO modem so most places I have internet access. Many places with bandwidth for live video. I have asked them to add an option for attaching a USB drive in addition to the modem

Bluetooth doesn't have the bandwidth for good video.