I am a web designer, and have been using WordPress for some time. For my new portfolio update, which I need to put up by the end of the month, I was aiming to do a client area. You would have a username/password, there you could view messages from me, schedule website maintenance for yourself, any outstanding fees (with ability to pay), and stuff like that? For people who have websites through me, I asked a few friend clients, and they agreed that it would be very useful! Especially with the volume of maintenance I do.
Any ideas? Coding? Plugins? It would be different content per client, same layout for everyone, if that makes any sense?