As a Django dev (currently, anyhow - formerly was largely Windows software dev), I think I would investigate Go, if we're talking purely from a 'fun' perspective.
From a professional perspective, I've been dabbling in Objective-C/Cocoa and the Android SDK (trying to dredge up old Java knowledge) - but for something 'new' I think I'd take a closer look at Ruby on Rails.
From a professional perspective, I've been dabbling in Objective-C/Cocoa and the Android SDK (trying to dredge up old Java knowledge) - but for something 'new' I think I'd take a closer look at Ruby on Rails.