Are there any wearable IP cameras? I'm trying to find a wearable camera (to mount on a helmet, or on the shoulder) that support live-streaming video over a WiFi-network or the mobile phone network (HSPA or LTE) to a custom video streaming server. Are there any such cameras that you know of?

I have considered using something like a GoPro HD Hero 2 with an Eye-Fi SD-card. That I believe would make it possible to upload the video to an FTP-server, and then I could provide on-demand streaming of the files that are uploaded. However, it would be really nice to allow live-streaming, and in that case the FTP-server setup wouldn't be a good option.
I use the Contour cameras, with a small transmitter-box connected to the camera. If you want decent quality footage, you should avoid cameras with built-in wireless streaming, as most really do not have the capability to transmit in full quality.