This circuit grabbed my attention of a cellphone controlled apliances with talking confirmation.http://3.bp.blogspot.com/-4NnCGdS1z5A/U42-l0Q8ylI/AAAAAAAAHsE/1x4nxNB0S-w/s1600/Circuit+for+cellphone-based+device+control.png
The idea is that we can cut the sound chip part APR9600 and connect it to an arduino. Then load several messages into APR9600 through the microphone.
Then make an educational robot head for children; connect one of Arduino Analog inputs to a sonic sensor. As you bring your hand closer, robots speaks of distance; maybe 5 or 6 different distances can be announced as per APR9600 capacity..Funny I did not see anyone connecting the APR9600 or WT588D to Arduino....(both are very cheap)