Most people I know here have middle names, and both my parents do. In my mother's family, usually the middle name is the name of a grandparent, great aunt/uncle, or an ancestor like that. Or it's swapped over, the first name is the name of a grandparent/etc. and the middle name is something more unique (or ... yet another ancestor). The eldest boys usually have their grandfather's name or similar - in my family, it's been variations of the Afrikaans version of "Christopher" for generations now. And since my family over there grew very large and spread out over those generations, there are hundreds of people with variants of the Afrikaans "Christopher"... I've got cousins with that name... second cousins... third cousins... even people who are totally unrelated except for being some branch of the family 100 years back have it... it's all over the place... ;;_;;
*cough* Back to middle names, I don't have one, and neither does my sister. My brother, other sister, and both parents do, and as far as I know, all South African family does. The Dutch family, however... it seems, this generation doesn't bother with middle names. All my uncles have one, and grandparents, too, but my cousins don't. And even those that do have middle names, it's rarely anything to do with family members - just cool names.