In-house person identification system
I think your Bluetooth suggestion is the most viable one.  However I would use the new BLE (Bluetooth Low Energy) standard as it will reduce the current consumption of the senders considerably.

You refer to the devices carried by the users as senders and the fixed room devices as scanners; the actual Bluetooth nomenclature is masters for the fixed room Bluetooth devices, and slaves for the senders since they will be going in and out of the network as people arrive and leave.

In addition to the senders and receivers, you are going to need a host Bluetooth device that receive all of the information from the fixed room devices.

The problem with Bluetooth (or any radio-based scheme) is that multiple room receivers will "see" each of the senders since the range will probably be at least 10m inside a house.

However it's possible to narrow things down using a RSSI (Received Signal Strength Indication).  Each master can compute its own RSSI value for the slave, and then these could be sent to a host computer which could do a triangulation calculation.   Here is a paper written on this topic.

Note that it is not necessary to actually do a Bluetooth pairing to get the RSSI value; one just needs to execute the command to do an inquiry and each of the RSSI values will be returned along with the MAC ID of the devices.   This is very convenient, since it means you never have to actually pair up any of the slaves with any of the fixed room Bluetooth masters.

We're not really supposed to provide specific product information here, I'll just say I have used the Bluegiga BLE113 on a couple of projects successfully.

Note: Beside BLE, I should mention that ZigBee is also an alternative.  It works in the same 2.4 GHz frequency range as Bluetooth and Wi-Fi.  It has the advantage that it uses a mesh network as a network model, which makes it easier to hop from one node to another (for BLE, you will have to engineer that yourself -- mesh networks are coming to BLE, but are not here yet).

The main disadvantage with ZigBee, as I see it, is there is no built-in transceiver in either PCs or Smartphones, like there is for BLE.  Why is that important?  If you have a smart phone in your pocket, you won't need to carry anything else to be recognized (such as a bracelet).