I've waxed poetic about the virtues of Windows Mobile in this space before, but I think I've neglected to mention a nice Windows Mobile application that shows off platform features and ease of deployment while providing some truly useful features. The app in question is Windows Live Search, and you can check it out on your Windows Mobile phone by browsing to http://wls.live.com. It'll deploy to your phone and install in a surprisingly short amount of time, and then will be accessible under "Programs" as "Search".
While the app does a lot of nice things like computing directions and finding local sushi bars, it's killer feature is the real-time metro area traffic maps it provides. If, for example, you were interested in whether it would be better to take the 520 or the I-90 across Lake Washington to make that meeting in Redmond (or whether it would be better to postpone and grab some sushi in downtown Seattle instead), Live Search can get all that for you right on your mobile device.
You can even check it discreetly during long running meetings - just don't try it while driving. 🙂
I bring this up here because the technologies used to build apps like this are well within the grasp of ISVs. In fact, some ISVs are taking business data and plotting them on maps to Windows Mobile devices using client-side transformations. This enables maps to be updated without a call to the cloud to re-render on every step. I'll blog about plotting client side points on maps soon - I think it's a very powerful technique that opens up a whole new class of applications for development.