It took me several years to realize that the plastic cups with lids and straws that are used for children at restaurants are considered “disposable” by restaurants. In other words, if you don’t take them with you, they will throw them out. These cups are very, very reusable, and can save you a ton of money on buying straw cups for your kids. They are typically plastic number 5 and hold up very well in the dishwasher. One caveat is that the lids are not as sturdy as screw on lids, so they don’t work well for wandering around the house or situations where they may get dropped. 
We use ours for meals at the table, for drinks outside and for parties and gatherings. Because they come free from the restaurants, if they do get lost or broken, it’s not a big deal. I don’t have any qualms about sending one home with a friend who needs a drink for the car or with the kids to the neighbor’s house. I have collected a couple of large stacks to use for children and adults at parties. This way I have plenty of reusable cups and I don’t have to buy disposable cups when I entertain.
Other uses for these cups include playing in the sand, in the bathtub, growing plants, and a variety of craft projects. Please let us know what creative ideas you have for these cups!
Even if you have too many already, don’t leave them behind at the restaurant. The server will just throw them away, and at the very least you can recycle them!
Happy Greening,
Alicia
I’m saving ours (along with the large yogurt containers) to start seedlings in in the spring. Punch a few holes in the bottom, put the lid underneath it to catch the water that runs out, and it’ll be the perfect place to start vegetables.
I’m really enjoying your blog (this is Sally from MMOTA)