All the little kids I know are so into dress-up, and there are adorable dress-up kits for boys and girls at Costco right now. For girls, it's always princess stuff, and boys always want to be superheroes. So cute!
I have to second what others have said about the lego though too.
Not sure if the kids are allowed to watch TV, but DVDs are easy to send. You can get some great educationonal DVDs too.
