I used to think that the "front pocket ploy" was a good idea. . . until a pair of thieves got my wallet on the Metro. I use a pouch-like money belt now. By the way your passport could end up getting ruined, especially in the summer, by sweat (or do you just "perspire?"), so either put it into a small plastic bag, or purchase one of the plastic passport protectors at a tabacco shop. They work great, and are less bulky than leather covers. My first passport had to be replaced when it got soaked in the summer!

Back up credit and debit cards are a good idea too. Enjoy your stay, and, "¡Bienvenidos á Madrid!"