Is there some way to list the devices that are currently connected via Personal Hotspot?

When using Personal Hotspot on my iPhone 4s I am frequently seeing an extra connection that I cannot account for. For example, I may have the iPhone plugged into a PC Using USB Tethering and another PC connected via Wireless Tethering but the blue iPhone Personal Hotspot banner display says there are 3 Connections.

Rather than trying to guess what other device is connected, it would be a lot better if there was some way to list the devices that are currently connected to Personal Hotspot. Does anyone out there know if there is a way to do this? Is there some kind of app available or iOS feature that will let me see a list of the individual devices using Personal Hotspot?

Many thanks to anyone who can provide some information on this.