How to add OG to the menu?
Do you need this in an existing menu? 

Personally I would do this with Views. If you have it installed try the below.


Create a new view
Add a Block Display
Set Access to Authenticated Users
Change the Basic Settings > Style to "Table"
Add Fields for Node Title &amp; Organic Group Post count
Add Filters for Organic Group Member "True"


This will now display a table with the titles and a "new" post count. You can make it look more like a traditional menu by changing the view settings further.