I thought it actually did take a weekend because when I say 'weekend project' I literally mean that I spent one weekend on it and then it was working. I posted some time ago about
http://bemyfirstcustomer.com which I thought of and then coded in a weekend.
Little projects are a really nice distraction and I use them to clear my mind. I've found out early on that spending all my time developing the same thing, https://mijura.com in my case, was draining. Short projects also let me test out new libraries, hosting providers etc. That said, a weekend project can prove popular and then consume an immense amount of time. This happened to me with http://vodafail.com, which I initially created while waiting on hold for customer service.