Second for the mason jar train. I prefer the wide mouth 1.5 pint variety. You can safely freeze, bake, and nuke these suckers, and I do.

I bring my coffee into work every day in one, then I rinse it and drink water or tea out of it until I go home. I have a few in the freezer full of curry right now, and a couple in the fridge pickling some daikon and carrots for bahn mi.

As long as you don't constantly drop them (I have yet to break one, and I've been using them for years) you can get a ton of use without ever worrying about what they might be doing to your food.

(edit: this is not a referral link, just showing the variety I prefer.) http://www.amazon.com/Ball-Jar-Wide-Mouth-Bands/dp/B00B80TJL...