My first favorite is Exposure, an app that lets you browse Flickr photos. Personally, my favorite thing to do in a boring phone meeting is to browse Flickr's "Featured" category, and find new wallpaper for my iPod. Which leads me to my only feature request: it doesn't let you save images to the local "Saved Photos" album. (What you can do, however, is open the image in Safari, and save it from there.) Exposure does much more than this, too -- browsing photos taken nearby, or searching for photos by keyword. Exposure is a great image browser all around, and it's free, but ad-supported. A premium version (sans ads) is $9.99.
The second is time:calc. It may seem a little strange, but I've always wanted a calculator that figures time instead of decimal numbers. As a freelancer, some of my contracts are retainer-based, so I have to calculate how much time I have left for a particular task after work has been done. time:calc does this effortlessly: just enter hours, minutes and seconds, and use mathematical operators as you would a normal calculator. For video editing, it also includes support for time code in a wide variety of frame rates. time:calc is $1.99, and well worth it.
Last but not least is my new favorite timewaster: Trism. Mike wrote about Trism in February, and I remember wanting it really bad when I first saw the video. It's an extremely fun Tetris-like game using three-sided tiles, and uses the device's accelerometer to determine which way is "down." It's not unlike Burning Monkey Puzzle Lab, for those that remember that game. Trism has three game modes, and a training mode. It's $4.99.
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