Avoiding road tires which collect grit One of my tires (the front) was replaced recently, and I notice that it picks up grit (i.e. tiny, sand-sized debris) much more easily than the cheap stock tire (still on the rear) that came with the bike.  This happens both when the road is wet as well on roads that have been recently resurfaced.  (In the latter case even though the road is dry, I still seem to get bits of asphalt along with occasional black gunk which makes the sticking worse.)

I have been told that grit sticking to the tire won't cause a flat, and if I don't scrape (which I always try to do under these conditions, although this is really annoying) I find the grit generally spins off the wheel eventually, but nevertheless it leaves me with an uneasy feeling.

When it is time to replace my rear tire, I would like to get a tire that doesn't have this problem.   However, I don't see how to tell by looking at a tire whether or not it will have this problem.  I do notice that my new tire does seem a bit shinier than the old one, but I don't know that this would be a reliable indicator.  Is there some foolproof way to avoid such a tire?
I tend to agree with @amcnabb, softer rubber will stick to asphalt better, but it's going to collect lots of junk. However soft tires will also live less than harder slicks, so anyway it's the balance between grip and durability. If you are not that worried about gripping the road in crazy turns, just search for harder rubber slicks.