I've used a ton of different things over the years for travel, camping, backyard cookouts at friends, impromptu picnics, etc and the best, easiest to keep together and keep clean, most durable, green, solution I've found yet is the Zelco Mangia 3pc set.
Stainless steel, the spoon and fork handles nestle into the knife handle, and all three working ends can then be capped by a snap-closed plastic top. Easy to keep a set in your daybag, glovebox, briefcase, whatever. The Amish used to always carry a spoon with them when going to neighbor's homes for big feeds, and I look at this set like that. I always have one fairly near.
I used to buy them three-four at a time and give them to fellow travelers, though I'm not sure the Zelco Mangia set is being made anymore. The last couple sets I bought had a less-durable plastic top, some of which eventually split or cracked at the snap tabs.
If anyone sees them for sale anywhere, let me know. ( NOTE:There is one place online, but they only take cards, not paypal, and it's an obscure site I've never heard of. My experience with some sites when they have otherwise unavailable items is that you can provide your card info and check out, then find out weeks later they don't have the item or they never send it, you have to fight to get your pesos back, AND they have your card info. With Paypal you might end up out some dollars, but they don't have all your info.)
I'll get more and your set will be on me.