Windows Phone 7 development: Some ideas to get you inspired.
I've collected a few examples of what people are doing on Windows Phone 7 and would like to share them with you:
Game: Ilomilo, simply beautiful game.
App: OpenTable, restaurants reservation app.
App: Shazam
App: Netflix
App: Feed Reader, read more about it here.
App: Foursquare, a location-aware, social networking app.
App: Flixster
App: WP7 MousePad
Game: Flight Control game
Game: Samarium Wars, a very well done little game, classic.
Game: Alpha Jax, another very cool game.
Library: SharePhone: Not quite an app, but an API for connecting SharePoint 2007/2010 with your Phone app. (Keep in mind Windows Phone 7 has SharePoint support built in the user interface, this sample is about building custom apps with SharePoint support)
Library: Phone 7 Action Pack, yet another library for making it easier to deliver some common app functionality.
Helper: Multi-touch simulator, one challenge we can have when developing an app for WP7, without having the proper device, is how to simulate multi touch on it. This sample (I haven't tested it yet but looks functional) shows how to simulate it on a normal desktop.
Game: Bye bye Brian, yet another game, nice graphics.
App: DoodlePad, a fun sketching app for WP7 (and it's free).
App: Simple audio analyser, interesting app demonstrating the possibilities around sound wave analysis/visualization.
Game sample: CPU Skinning, a very nice XNA sample showing the 3D graphics possibilities on Windows Phone 7. If you want to learn about building 3D games on Windows Phone I'd recommend you to download this source and have a very good look at it. (Tip: Try to add gesture support, make it able to zoom in and out for example. It took me a while to get it to work)
App: Papersketch, simple but quite nice little toy.
Inspired? Start planning yours then! And keep an eye on our WP7 dev challenge that will happen in October.