>Northern part of South America
>Souther part of South America
Looks needlessly fragmented and imprecise. What is 'Southern part of South America'? Cono Sur? Then Brazilians from Minas Gerais and Porto Alegre are in different groups? Was that the intention? Why 'Southern North America' and not Central America? Where does Caribbean belong? Middle Asia (say, Kazakhstan)? Is Spain Western Europe or Southern Europe? Is Czech Republic Eastern Europe or Western Europe (since you don't offer 'Central Europe' as an option and some Czechs may be unhappy with identifying as Eastern Europeans)? Is Estonia in Eastern Europe? It damn well is in Eastern Europe, but some Estonians identify Estonia as Scandinavian.
Next time you guys should use some well established scheme such as this one http://en.wikipedia.org/wiki/United_Nations_geoscheme and just link to it in the post so no one is confused.