Check out White Noise Baby for iPhone and iPod touch. Made by the same folks who created the popular White Noise app!

http://www.tmsoft.com/iphone-whitenoisebaby.html

Version 1.0 Features:
- English alphabets are displayed sequentially (like flash cards).
- Alphabets are pronounced (Optional switch).
- Pause button to stop at an alphabet
- Reset button to start over
- Timer can be adjusted to delay display of alphabets

http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=324385183&mt=8

This one works for this too, launches a little quicker than White Noize and the sounds are of better quality http://www.sleepybaby.net

Proclaiming only Appleboys use this application is a little bit harsh on the iPhone's market. I've seen some people who were otherwise completly clueless about computers with iPhones.