We maintain several sites, mostly for fun, but also to experiment with "separation of concerns"
Like everyone else, we're still experimenting with all this newfangled community plumbing stuff, to see how it all works.
 

Separation of Concerns: 

Recently we've made attempts to separate concerns into separate sites.
 
Most people only really care about one thing - such as programming or services, or in the case of family or friends, Pete's personal stuff. So keeping things separate keeps visits a little bit cleaner.