Think of Tumblr as micro-blogging on steroids (technically, it’s called “tumblelogging”). Whereas Twitter and similar services limit posts to 140 characters or less, Tumblr lets you post updates of any length, although it’s best suited to short-format posts. Tumblr bridges the gap between full-blown blog and micro-blog. Tumblr is also an option for designers and creative people, because it gives y