If you've ever shown off your iPhone's photo collection to friends, you know that trying to give everyone a good view often results in an annoying battle against sensitive accelerometers. Use your thumb to lock iPhone photos in place.
iPhone app maker Bjango reveals this little tidbit in a blog post meant for developers working on their landscape/portrait layouts, but it's a good tip for use in certain applications, Photos included. Simply rotate a photo the way you want it shown, then hold down somewhere on the screen with a finger to keep the photo rotated in that way, regardless of how you tilt your screen. With the 3.0 and later firmwares, you'll probably get a little "Copy" bubble prompt over your finger, but it's worth the minor annoyance to avoid the bigger annoyance of "Oh, wait, wrong way ... wait, no, it should be ... Can you see it, Tom?"
Works on iPod touch models as well, of course, but doesn't seem to work in Safari. Tell us if you've found another app the "finger lock" works well with.