Haha - I was just going to post 'chopsticks win!'
Well-rinsed yogurt containers with snap-on lids of various sizes. I use a lot of those, for cups and for storing plants during 100% water changes in Demyx's tank, storing fiddly extra bits of stuff in, food, supplies... I just make sure to rinse them super well in hot water before use.
Plastic milk containers with built in handles. I keep pre-conditioned water in those, very useful.