I always wanted to create a plugin that allows me to edit the posts from front-end, through some kind of Ajax interface but never had the time to write it. However, I have just found a plugin that does exactly that and it's lightweight, fast and does the advertised. It is called Front End Editor. To use it, just double click the post or title area and inline text editor will appear where you can edit the post directly without going into the admin panel. Great for fixing those typos.