I've posted a collection of tutorials and example applications for Windows Phone, the first series is based on the "31 days of Apps" by the guys at apps amuck. I find it better by building real applications and their series was great inspiration. While these won't produce marketplace ready applications they're the first step on the way.
Glance and go with exactly how much money you have left in your allowance. Enter purchases quickly from the home screen, no more fiddling with your phone at the store counter.
Quickly prioritise upcoming tasks, see only what you need to do each day, week or month. Easily set tasks to today, tomorrow or this week rather than fumble around picking the date on a calendar.