I was in the pub last night with a friend, who, to maintain his anonymity, I will refer to as "Jerome". We have a mutual friend (here known as "Lorraine") who has recently moved house. Neither "Jerome" or I had her new address.
We were pretty sure this was an oversight on "Lorraine"'s part.
To discover her address I came up with a plan; that we would come up with an object that was irresistable to "Lorraine" and put it on ebay. When she bought it, we would find out her address.
"Jerome" then texted "Lorraine" to ask for her address, on the pretext that he wanted to send her several tins of sild.
She replied with her address immediately.
If there is a lesson to be learnt from this, and I'm not sure there is, it may be that there are better uses for tracking devices that are completely irresistable to one person but undesirable to everyone else  than to auction them on ebay to find out the address of the person who desires it.
This completely pointless post has been brought to you in association with beer and agreeing to blog something while in the pub.
 Refinements to the plan included "Jerome"'s suggestion that the object be a tracking device of some sort in case it were to be delivered to an address other than "Lorraine"'s, and my thought that the object, while irresistable to "Lorraine", should be found undesirable by everyone else on Earth.
 Lightly fictionalised it is:
221B Baker Street
 If it were undesirable to everyone but a small group of our friends, that would also be okay.