While I have not been explicitly conscious about mixiGraph until a few days ago when one of my MAIMIKU, Ben, introduced it in his diary at mixi, I would say mixiGraph is such an amazingly powerful tool. It shows the diagram of your MAIMIKU families.
Here is how it works (I prepared this especially for non-native-Japanese MIXI users, with win XP, I think for MAC it is more or less the same.):
Make sure you are logged in to MIXI.
1. Go to http://www.fmp.jp/~sugimoto/mixiGraph/
2. Click mixiGraph.exe underneath Windows版, ダウンãƒãƒ¼ãƒ‰&インストール
3. Save the program in your PC and run it.
4. The diagram should come up, with yourself centered surrounded by your MAIMIKU members. The arrow connecting any two faces indicates the MAIMIKU relationship.
5. Click, then, one of your MAIMIKU members.
6. Yet another diagram should expand: now you have two diagrams, one for yourself and another for one of your MAIMIKU members, with you and your MAIMIKU obviously connected.
7. This way, you can track MAIMIKU’s MAIMIKU’s MAIMIKU’s..all the way down until your PC screen gets small enough and might find MAIMIKU’s MAIMIKU’s happens to be MAIMIKU of another MAIMIKU. (Note: Ashitao or footprint will not be notified.) When all the diagrams can not be shown in the screen, use right-click and choose [A]全体を表示 to show them all in the screen.
Not surprisingly, there is the dedicated community inside MIXI with 7,154 members. Of course, I have joined it. It seems mixiGraph itself is developed by its community leader, Koji Sugimoto.