I find it hard to strike up conversations while on the road for business or fun, but when I do find a way, they usually make the trip much more meaningful and memorable. Over the years, I've found a few nice ways to meet people, make travel more fun and go home with my bag a little lighter.
Step 1: One Picture Is Worth a Thousand Words, Especially If You Don't Speak the Language
1. Take a few cheap postcards from the area where you live. Show them to people you meet along the way to give them an idea of where you live, even if you don't speak their language. Leave them with a new found friend (after writing down the contact information you are comfortable with). This is especially nice if you meet someone you would like to show around your part of the world or would like to swap photos with after your trip. A few business cards are handy too, even on vacation.
Step 2: Toys
2. Take a few inexpensive, small, safe children's toys. Pull them out when the toddler in the seat next to you starts fussing. While traveling, give them away and make some little kid happy. (Always ask the parent first, of course).
Step 3: Shiny Baubles
3. Take several small "trade items" that are unique to your area. Barter, trade or gift them to someone who goes out of their way to help you. Never use them instead of a tip, only to show appreciation.
Step 4: Books - Remember Them?
4. Take a couple small paperback books. In addition to being non-power dependent, you can leave them along the way, trade for someone else's book, or leave them for others to enjoy at the hostel, local public library, school, etc.
Step 5: Don't Lug a Laptop
5. Forget heavy and expensive electronics to back up your photos. SD cards are tiny and cheap. If you change them out every day or so, you won't lose memories even if your camera floods or is stolen. When full, throw a little square of "post-it" on to show you have used them so you don't put them in your camera again.
Step 6: Multi-task
6. Try to carry items that serve a dual purpose. For example baking soda that you can use to brush your teeth or make a paste with water to treat insect stings. T-shirts or sporting shirts from your area can be worn and traded.
Step 7: Poncho
7. Unless you know your are going to a rainy destination or have checked the weather and are headed into bad weather, stop worrying about the space for a rain coat. Carry a small cheap plastic poncho that is one step better than the flimsy, shreddable ones. If it gets left on the train, you haven't lost an expensive coat. You can sit on it at the beach, or on wet park benches, etc. Give it away or trade it at your last stop to make room for something interesting you would like to take home.
Step 8: Play That You Can Share
8. Carry a kite, frisbee, soccer ball, harmonica, etc. No common language is needed and they are great ice-breakers. If you can afford to, gift it to someone who shares your interest during the trip. This makes it even better.
Step 9: Emergency Laundry and Rental Car Access
9. Take a rubber sink stopper and a lightweight 12' length of cord for drying clothes-even when you are sure you won't need them. If you have room, throw in a couple wire hangers for hanging clothes and getting back into your rental car when you lock the keys inside.
Step 10: Back-up Your Back-up
10. In the personal item you take on the plane with you, always have one lightweight change of clothes. When your seat mate spills their drink on you, they lose your luggage (or your "carry on bag" needs to go into the cargo hold and mysteriously disappears), life will be more pleasant.