Here's a State Department website link that tracks the non-natural deaths of Americans abroad by month, year and country. Most common cause was vehicle accident deaths. The list also includes suicides and drownings.
This is a recent list of the deadliest, most violent countries for Americans abroad from January to June, 2009, for what it's worth:
1. Mexico: 126 deaths (61 in accidents, 22 drowned, 6 suicides)
2. Costa Rica: 16 (9 in accidents, 4 drowned, 2 suicides)
3. Philippines: 15 (3 in accidents, 6 suicides)
4. Germany: 15 (7 in accidents, 7 suicides)
5. Honduras: 14 (2 in accidents, 2 drowned)
6. Dominican Republic: 14 (four in accidents, five drowned, 1 suicide)
7. China: 10 (6 in accidents, two suicides, one disaster victim)
8. El Salvador: 8 (2 in accidents, 4 drowned)
9. Jamaica: 8 (5 in accidents)
10. Japan: 7 (2 suicides)
11. Thailand: 7 (3 suicides)
From the Chicago Tribune
UPDATE: Of course, a skeptical view of these numbers would be appropriate, even from the best source. Statistics don't tell the full story or predict the future. In fact, the more I look at this site, the less reliable it gets. For example, there are no comparable statistics available for the U.S. (pop. 301 Million). For all of communist China (pop. 1.3 Billion), there are only ten unnatural deaths in the database in the same time period (Jan-June/09) and in India (pop. 1.1 Billion) there are only four. In Indonesia, 4th largest country in the world (pop. 235 Million) there are none recorded. Canada with a population of 33 Million has only four. Despite this valiant effort on the part of the State Department, perhaps these statistics have to be taken with very large flakes of salt. Shouldn't the U.S., the list maker itself, rank near the top of this list? Clearly, this list is a work-in-progress, or perhaps work of the future.