Why do we need the [app] tags? Why need the LinktoApps thing at all? You could just right-click the app's name in iTunes and click "Copy iTunes Store URL", and paste it here or wrap it around with tags like any other link?
For example, there was a favorable review of the Space Ninja game over at touchArcade today. If I want to link you to the game, I can type [app]Space Ninja[/app] and have it come out [app]Space Ninja[/app]. Easy as pi.
When I tell people about iPhone and iPod touch apps, I sometimes take an extra step, and give them a URL to AppShopper, e.g.,
That way, they can read about the application and see screenshots and a price history without even launching iTunes. One click at AppShopper will take them to the application in the iTunes Store.