Which is the largest interest group in mylot?

Looks like you have some research to do. Have you included interests of your own? They will show up on the left hand side of the screen. You can see from there what the most popular interests are at the moment. I feel that most people post under "general" . But some post under specific interests. Unless you add interets of your own I'm not sure how you will find out. Check "hot topic" of the day as well. You will see the common interests there.

Mylot.com is also, one of my interests. So most probably I belong to that group. But I have so far not being interested of the structure of these groups. I think to respond to your discussion one must do some extra research taking up his time. Very unlikely that you will get responses to this discussion.