For example, I've been playing with the "more.groupware" (
http://mgw.k-fish.de/). I use calendar, contacts, files, webmail, to-do and notes modules in that one. Mambo already has most of such modules. All we need is that somebody to interate those modules in a groupware sense (i.e. appropriate users can access to appropriate modules and data.) (I wish I could do it but I don't have the technical knowledge.)