Dd3 has recently had a big burst of rock and stick collecting, fortunately we live on a mountain so that's not hard to do. The tough part is all the places I'm finding them. She's not 'classifying' or anything, but making little cities, rock 'stores' and other stuff with them. As usual with her, if you accidentally disturb one of her set ups, well, prepare to be chastised.
And she is still very into cars, trucks, helicopters, etc.

Ds9's most surprising hobby still has to be ballet (not sure it has much to do with being gt, but he says ballet is fun partly he doesn't end up thinking so much (??) One of the instructors used to call him 'dreamer', however, so I don't know how much less daydreaming/thinking he is doing.
Otherwise reasonable adults continue to skip a beat when they hear the words 'boy' and 'dance' together, it's even funner when the actual word 'ballet' is used.
(Rockets and drawing don't get nearly as many 'reactions'. )