I've always been the type to run the softest tire (within reason) that I can, even on the street. While I don't run dedicated slicks I prefer great traction once up to temp at the expense of a little greasiness in the mornings.
However, a byproduct of running such soft tires on my daily mount is that they tend to pick up everything in the road–be it pebbles, glass, etc. And last night, while I was wiping down my 2009 Yamaha R6 I noticed a shiny spec in the tire. It ended up being a 1/4" piece of metal that looked like the bottom section of a tiny nail. I promptly pulled it out and all was fine.
However, had it been deeper or entered at a different angle, pulling it out would have caused a flat so be prepared to deal with the tire if you're gonna pullout the intruder. On the other hand, had I neglected to pull out the metal, it would have slowly driven deeper into the carcass of the tire, likely causing a flat.
So moral of the story, try to watch for debri in the road but it's good practice to check your tires every few days or once a week just in case you missed something.
http://www.yamaha-motor.com/sport/products/modelhome/8/0/home.aspx