Multi-Destination plane tickets have been commonly referred to as "round the world" tickets. Both are simply a series of airline tickets bought together as a whole at a cheaper rate than if you were to purchase them all separately. I purchased one such ticket in 2006 for $2500, and flew from Seattle to Hong Kong (via Los Angeles), then to Singapore, Indonesia, back to Singapore, went overland through Malaysia and up through Thailand, where I caught a flight to Nepal. My return trip was almost as lengthy: Kathmandu to Bangkok to Hong Kong to Vancouver B.C. to Portland, Oregon.
The pros to buying a multi-stop plane ticket are obvious. It's cheaper, it allows you to plan ahead and stay organized, and sometimes you can turn a layover into another adventure! When purchasing your ticket, the company you go through should let you know of any free layovers along your itinerary. For example, if you plan to fly from the west coast of the U.S. to Singapore, you will most likely have a connecting flight in Tokyo or Hong Kong. Rather than simply switch flights, why not spend a few extra days exploring a new city? Better yet, go overland to your next destination if you can. Take a train or a bus across the country. Your overall ticket price will be cheaper and you can explore more of the country.
The main drawback to purchasing a multi-stop plane ticket is that of flexibility. For the traveler who doesn't wish to be tied to a schedule, one-way tickets may be best. It's much more expensive, but the sense of freedom might just be worth the extra buck. However, for the budget traveler who doesn't mind planning a route, the payoff is huge. It could just mean an extra month in Nepal, or more fun souvenirs to bring home for family and friends.
I highly recommend Airtreks.com for purchasing a multi-destination ticket. While other companies can and will do a multi-stop ticket, Airtreks.com specializes in them, and has an easy to use trip planner on their website. They even give you an immediate price range so you can compare routes and start planning your trip right away! Plus, the travel consultants are incredibly helpful. When I had to change some dates on a couple of my flights, my travel consultant took care of everything quickly and made it very easy for me to make changes.
For many people, a multi-destination airline ticket is the perfect way to see a lot of places for less money. Sometimes you can visit multiple countries for the same price as a round trip ticket to just one country. It's definitely worth a look for any trip you might be planning, to Southeast Asia and beyond.

