Tracking devices [semi off-topic]

[Gwilym Evans]

I realise this list's topic is wireless data networks but I figured I if 
I'm going to catch the attention of someone who's knowledgable in the area, 
this would be a good place to try.

Does anyone know of any portable tracking devices and services available in 
Australia? (or available internationally with access in Australia). A good 
example is the MicroTrax system here: 
http://www.govcomm.harris.com/programs/microtrax/ but I doubt this is 
available to the public. What I'm interested in mainly is tracking 
expensive pieces of hardware. It's mainly out of curiosity though, to see 
if such a system exists, how it works and the kind of costs involved.

Like buy an attachable device and stick it inside, say, the base of a new 
lcd screen you just invested in and later track it down if/when someone 
attempts to steal it (ofcourse the more goody-two-shoes of us might call 
this a lesser form of entrapment ;).

TIA,
Gwilym.

PS. I'm trying Eudora at the moment, apologies if this gets sent in HTML.