notes
Some apps try to synchronize their own internal lists of groups with webgroups. Please avoid this if at all possible!
Having a local cache of groups is sensible (particularly for auto-generated groups, which only change once a day anyway), but if you're periodically polling all the groups on the system, you can end up using quite a lot of resource. If you must do this, then remember that the webgroups APIs support if-modified-since requests.