Usefulness can be interpreted in different ways by different people. To me, a site is useful to me if it enhances my skill, increases my knowledge or just makes me smile. For many, usefulness means making money only.
Dave's Daily does the last of the above to me. I enjoy reading the feed of Dave's blog for quite some time now. Funny pictures and weird news are my daily dose from Dave's Daily.
Here are two funny pictures from his recent post that displays weird warnings.