It was only a matter of time! News@Nature is running a World Cup special, with, among other things, pieces on the science of footballs and boots. Some of the items are available only to subscribers (we can see only those items included in a standard journal subscription). Go to http://www.nature.com/news/specials/worldcup/index.html
The Chartered Society of Physiotherapy have produced a "2006 World Cup survival guide", on footballing injuries, available in various forms at http://www.csp.org.uk/director/physiotherapyexplained/features/worldcup.cfm. There is a Flash version, an HTML version, and a printable PDF version.
Finally (and rather peripherally), I am conducting an experiment in the Guardian's Fantasy Fussball, by picking a team made up of as many African players as I am allowed. Watch this space!