Tickling is a very useful cultural device through which touching among family members can be emotionally coded as neither sexually exciting nor repulsive, but rather as neutral feeling.
Oddly enough, I can tickle myself between my navel and the front corners of my hips. The sensation is still surprising, and makes me burst out laughing. I've never tried doing it for any length of time, however.
Go read the whole article and the comments. You might not want to do all the things suggested, but most of them are sensible ways of saving money and eating better.