I usually only have cups at the table while inside but outside is different. I bought some cheap sippy cups and put their names on them and take those outside with water in them. This way if they lose them at the parks it's not the good ones the parents send. They are running around outside and it's hot so I like to offer a drink.

I will throw them in my outside bag, add a couple bottle of waters and fill at the park or in backyard. Before coming in I dump the cups so it doesn't leak in my bag and I'm not juggling cups and children!