From time to time, yes. I looked for a truck, not seriously, for years before I found one. When I finally went to buy, I had a great idea of the market, value, and condition. Now I have had mine for over 2 years, I still look from time to time.
I do this for everything. I will look at stuff I have no intention of buying, but sometimes it comes up with a good deal too...
I was looking at Plymouth Acclaims one day for reminiscence (my first car, I sold it to buy my first truck), when I found a nice one 30 minutes away. I thought hey, let me just look. I came home with it. Got a year and a half and 18k miles out of it with nothing other than oil, a muffler, and 1 set of good used tires, and I sold it for what I payed, even with a blown head gasket! You never know, so we keep looking.