On my current and previous Android phones (HTC Magic with stock Android 1.6, and Samsung Galaxy S with 2.1 and TouchWiz) there have been pretty good alarm clock apps that allow you to set a a variety of alarms with a variety of timing and days. This gives you the handy ability to set different alarms for weekends and weekdays, for instance. Unfortunately, I often have the experience of looking forward to a nice lie-in on a holiday but getting blasted awake too early, because I forgot to switch off the alarm.
What I'd like is an app that either adjusts the built-in alarm clock to automatically set the weekend alarm when a personal or public holiday falls on a weekday, or one that replaces the built-in alarm clock and offers this facility.
I guess it could pull info on public holidays for my country from a public feed (pretty sure Google Calendar publish one for most countries) whereas for my holidays it could pick up specific all-day appointments with certain text in from a nominated Google Calendar.