The 2010 ARRL 10 Meter Contest was on today and I spent some time making contacts with amateur stations that were taking part in it. The band was open and conditions were good. I kept a log of all the stations I heard. I was listening between 1630 and 2145 UTC. Mostly I was logging stations operating in Morse code (operating from 28.0 to about 28.05 MHz) plus a few in SSB (around 28.5 MHz). Logged stations from the United States, Canada, Belize, Mexico, Brazil, and Argentina. 10 Meters is interesting. It's closed much of the time, then opens and easily supports global propagation at modest power. Sometimes it opens to one particular part of the world. Today, from here, it seemed to be open only to part of South America - I didn't hear stations from very many countries, but I did log six Brazilians, all from the southern part of the country, plus one Argentinian from the same general region.
I've said this before but will repeat it. DXing amateur stations is something SWLs should consider doing more often. With shortwave broadcasting on the decline, there are many parts of the world that you may only be able to hear on shortwave on the amateur bands.