There are many kids out there who could be considered budding curators, without even realizing it. I should know, I was one of them.
Whether they want to collect minerals and fossils, Kinder Egg toys, shells, books, Lego or Barbie dolls (the list is endless), collecting is a great way for kids to learn something new, get creative and get focused. It also teaches them to care for and develop something that belongs to them and only them. I remember I was immensely proud of my little rock, mineral and fossil collection, even though it wasn't that big. On vacation I didn't spend my saved up cash on souvenirs that would ultimately end up in the garbage, but instead carefully and happily picked out new minerals to show off. It also gave me something that I could teach my parents about which was a great feeling.
Whether or not collecting develops into life long hobby or not, it will teach kids skills that will always come in useful as they grow older and give them a pride in their 'work' too.
The Smithsonian Museum has a great little interactive web section on just this topic. Check it out.