The App Store loves novelty camera apps, but some (below) are more useful than others. This week, we also found a video streamer, a price-shopping helper and eight extra mouths for your mouthy self.

iPet Photo: Whether your cat or dog is turned on by monkey sounds, bird sounds or the sounds of other dogs, this camera app draws their attention for a quick snap. I tried it on my dumb cats, and it works fine, especially on the dumber of the two. Costs a buck.

Air Video: I had this local wi-fi video streaming app up and running in no time flat, serving up a MPEG4 video from MacBook Pro to iPhone in seconds. As you might have guessed, it does require a bit of Mac or PC software running, but it's pretty unobtrusive. Nice way to watch movies when you should be doing something else. File compatibility is a little thin, but there's a "convert" function I didn't get a chance to test fully that might be very effective. Good way to spend $3.

PriceOfUnit: For nerds with a grocery fetish (like me), you can comparison shop the price-to-quantity ratios of everything from olive oil to pet food. It's a little rough around the edges, but a good thing to have if you really want to gauge the value of your condiments. And it's free.

MouthOff: A well designed novelty app that gives you an assortment of moving cartoon mouths, this moves the cartoon to mimic you actually talking, by reacting to the pitch and volume of your voice. It's surprisingly well synced, though some mouths (green monster, gold-toothed pimp) are cooler than others. (That dog face reminds me of the Ballchinian from Men in Black.) One dolla make you holla... literally.

ReplayCam 25shot!: It's no Cycorder, but this subtle multiple-shot camera app lets you make temporary videos, and save frames as stills. It will even save all the shots in a pretty 5x5 grid, assuming your subject is pretty enough to be looked at in a 25-shot matrix. It's $2. (Macworld reviewed it in greater depth.)

This Week's App News on Giz:
Amazon Kindle Is Now an iPhone App

Watchmen Getting an iPhone MMO Game

Cydia Opening Paid App Store for Jailbreak Apps

This iPhone App Will Result in At Least One Accidental Shooting

This list is in no way definitive. If you've spotted a great app that hit the store this week, give us a heads up or, better yet, your firsthand impressions in the comments. And for even more apps: see our previous weekly roundups here, and check out our Favorite iPhone Apps Directory and our original iPhone App Review Marathon. Have a good weekend everybody—your regular iPhone Appster, Johnny "Egypt Me" Mahoney will be back from Cairo next week.