Here's a tip for the Windows Phone photo app. It works for WP7 and WP8. If you've got a photos folder with lots of pics in it, you can quickly scroll through them.
Usually, you'll open a photo in the folder and swipe through to other photos.
But if you pinch-in the photo, it'll create a "filmstrip" of pics in the folder which is much faster for swiping through.
When you get to the photo you want to view, tap it and it will become full-size.
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