I’ve been using Google Apps to power On9 Systems for sometime. The great thing about Google Apps? It gives me the flexibility to host email/calendar and documents there while having web hosting on On9 System’s server. This gives me the ability to create applications and host them locally.
Am also experimenting with ways to create a support forum for customers using Google Groups. At the moment, I’ve got a wordpress blog at support.on9systems.com but think its prob better to use a discussion forum.