Framed photos of the kids is my go-to gift for assorted grandparents, especially my mother, who really doesn't want any more 'stuff.' I usually try to find a tasteful frame, and I keep the pictures small (4x6 or 5x7), because I'm familiar with family members' decor. (My mom wouldn't want anything she'd have to hang on a wall, for example).
I don't generally give framed pictures to other extended family members (aunts, uncles, etc.) although I might give them 4x6 or 5x7 copies of photos of the kids (we usually have them professionally done). This is because, honestly, I don't really want to have to display framed pictures of all my nieces and nephews.....I just feel like it gets excessive, and I assume my extended family feels the same. By just giving them unframed pics, they can choose to frame them, stick them on the fridge, or toss them in a drawer....whatever they want.