Sometimes the simple things can be modified and controlled with an Arduino to enhance their use or operation. One example of this is by the "coolarduino" people who have hacked an inexpensive FM radio onto a protoshield and controlled the tuning function. The radio is based around the older Philips/NXP TDA7088 which seems to have been cloned and used in various cheap receivers. The hardware modification is quite simple and could be the base for a digital-preset FM radio control on a tight budget.
So if you see a cheap radio in the $2 shop, check it out and have some fun with it by starting here. And for more, we're on twitter and Google+, so follow us for news and product updates as well.