How to tell a girl that you want only to stay as friends?

Put in your blog, or perhaps tell her directly, something like, "blah blah so busy blah blah. Sure am glad I don't have a girlfriend atm, she'd be so neglected"
Or possibly, "My buddy tried to introduce me to this girl, but man, I really don't have time for a relationship right now, got way too many claims on my time and attention as it is."