strobist info:
full CTO sb-600 w/ silver brolly camera right.
Post process tweaks:
Light, contrast, color and cleaning the BG in Lightroom 3,
Merging the girl on the left from another image and separate light & softness for kids and BG in treatment in Paint Shop Pro X2. (latter with Juza's selective sharpening method: www.juzaphoto.com/article.php?l=en&article=24)