In many ways, Barack Obama and Joseph Biden are opposites. Obama is cool and even in his demeanor, while Biden is hot-tempered and mercurial. Obama is analytical, while Biden is practical. Obama is new to Washington DC, while Biden is an old Washington hand. Obama's expertise is domestic; Biden's forte is foreign policy. This Obama-Biden yin yang t-shirt reminds us that sometimes divergent traits can be complementary and productive when placed together.