[c-nsp] Monitoring device w/phone and PC behind it

[Netfortius]

Let's say I have a "monitoring" device (imagine a sort of tap), with its own 
MAC address, and which I want to connect to a Cisco switch port. Into the the 
same device (acting transparent to the traffic behind it), on its opposite 
port, I plug a phone, belonging to a voice VLAN, then, behind the phone, a 
PC, on its own VLAN. My device will also be part of a VLAN, but neither that 
of the phone, nor that of the PC "behind" the phone. This device will be 
transparent to the traffic flowing through it, from the phone and PC, to the 
upstream Cisco switch, and on further (with the exception of recording some 
of this traffic characteristics), but will need to be communicated with, from 
behind the Cisco switch it is plugged into. Here are my questions:

1. How would the Cisco switch port have to be configured, to accept this chain 
of devices? I understand that a phone and PC behind it would allow some sort 
of Cisco proprietary port configuration (auxilliary - somehow hybrid, still 
802.1q, but not really trunk mode), vs. either access or "pure" trunk, but 
dealing with three VLANs (two "data" ones, for my device and the PC, and on 
voice one, for the phone) makes me think that the auxiliary port concept 
won't work. But then the challenge becomes: if I use many such devices, on 
many phones with PCs behind them, I will end up with a mess of trunk ports - 
really not manageable, let alone risky

2. How wold 802.1x implemented on the Cisco switch port work in such a case 
(assuming question "1." gets answered)?

As the above scenario is somehow theoretical, somehow rooted into what I would 
like to implement as a sort_of traffic cop, with devices capable of doing 
such, I would appreciate comments of any sort.

Thanks,
Stefan