...is collecting other people's hobbies, and especially reading about all the specialized tools and equipment and guidelines necessary for the performance of said hobbies.
Lately I am collecting the sport of "dog agility."
Hobby-collecting has its own specialized tools and equipment of course:
1. A computer
2. An ISP
3. A Web browser
4. A Web search engine
5. A Library card
I have yet to find an association dedicated to my hobby though.