Re: Real examples of trackers
Another example:
Barter networks, where we use a tracker for Offerings and another one for Wants.
In action here (in Catalan):
- Offerings: http://intercanvis.net/Ofertes
- Wants: http://intercanvis.net/Demandes
Items are linked from one tracker to the ones in the other which belong to the same user, to ease the task of transactions... (you offer this that I'm interested for, and you are requesting that, which I might have or get for you... etc)
There is also a profile in progress for that which you can test at least this basic behavior already (and in English 
:
http://profiles.tikiwiki.org/Barter
HTH
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