It's amazing how popular sushi has become; there seem to be more sushi joints around than coffee shops these days. If it is made with sustainably harvested fish it is probably the healthiest of takeout foods. However take-out sushi is usually served in disposable plastic trays with lids. That's why the designers of Sushecō came up with their clever reusable sushi tray; they estimate that half a billion takeout trays are thrown out each year.
They have come up with a clever design that you can carry flat, and that then pops up to double its height to carry up to eight standard sized pieces and are raising money on Kickstarter to put it into production.
However that doesn't diminish the fact that this idea could make a difference. And there is no reason you couldn't put a sandwich in it, either. You can support it here on Kickstarter. Now excuse me, I have to eat my sushi and I don't do it by my computer. More info on Kickstarter