Audioboo Let's you record up to five minutes of audio and post it to the web. Great for recording kids reading aloud!
License Plate Game Provides an ongoing game for my family as we have a lengthy commute to school.
gFlash+ Flashcards & Tests Nice interactivity with Google Docs Spreadsheets. Help your child to study by putting lists of words and definitions in a spreadsheet and link it to this app. The app will take your lists and make create digital flashcards and other games.
GorillaCam Fun photography app that's especially useful if you buy their tripod for your iPhone. Rig your iPhone up to take pictures from all sorts of angles. Include the entire family using the timer feature.