This is something that I like to do. It is especially nice for smaller or newer fandoms that don't have an OFU or official adoption site. Many of the various mini types now have pages on the wiki that describe them--what they look like, personality, what they eat, etc. Then it lists all the names of minis that have been located and who adopted them.

Here are some of examples.

This is the new one for Sanctuary that I just finished

Stargate SG-1

A-Team has a little different format

Left 4 Dead demonstrates another possible format

Anyway, this is an easy way to keep track of who owns various minis, whether they've been discovered or not, etc.

It tends to vary. A lot of mini's are kept by the agents who found them as pets [Just take a look at Cali and Miah's Response Center for extreme mini care.] while others are put up for adoption for other agents to adopt for thier own stories.