I am moving away but don't know what to get my nieces and nephews, to whom i am very close.?

I am moving out of the country and i have five nieces, ages 12,10,8, 2 and 1 month....and two nephews ages 7 and 5. I am very close with all of them, like their second mom, and i dont know what to get them - i am looking for gifts to give them that they will have forever, and always think of me. I am of course giving them a google voice number in which they can always call me, and there is always skype, and I am going to give them a clock so they can know the time difference (even thought i would want them to call me anytime...)

So any ideas would be great. I can not afford anything too extravagant...and i want to take each one out for a day just with them. But i want to give them something they can keep always, and not grow out of or break.

Any suggestions would be appreciated