Notifications are a bit of a problem with web apps. It's much easier to do everything client side on a mobile device and I haven't figured out how to elegantly implement a notification system on the server side. I could potentially do everything by email but that brings a whole bunch of other headaches with it if I don't want to be blacklisted as a spammer. Currently I'm looking at appcelerator and adobe air to make the app more accessible to a wider audience but that's a little ways away.
