Different Site name and slogan for Organic Groups based multisite architechture
Open Atrium (6.x) uses spaces to save different configuration for each og, this may be helpful.


  Spaces is an API module intended to make configuration options
  generally avaliable only at the sitewide level to be configurable and
  overridden by individual "spaces" on a Drupal site. It has been
  described as:
  
  A way to make one Drupal site act like several sites A way to provide
  much more configurable, full-feature Organic Groups or user homepages
  A generalized API for contextual configuration