I don't know if your dad has one yet, but maybe a weather station?
Something that will tell him the indoor and outdoor temp at the least. I have a Oregon syentific thats about 3 years old and love it. Something about being able to see what the temp is outside... I don't know. Sometimes mine will say its supposed to rain , but it might have something to do with humidity level outside.
http://www2.oregonscientific.com/shop/default.asp?cid=2