I've been putting off setting up multisite on my localhost for ages, mostly because in the past I've found getting Apache virtual hosts to work can be a bit tricky: not impossible, but the sort of thing where I could easily lose an hour on a minor thing I've forgotten to do. And after all, with a shiny new iMac and a hard drive whose proportions I can't even remember, why not just 'drush dl' all over again?