I'm like this with certain friends, depends who it is. With close friends I normally talk so much there's no room left for awkward silences. Anyway, say yes and pick up the phone! If a huge silence comes on then just make an excuse and say you'll speak to him later. And if you meet up in person just think of them more as comfortable silences...not awkward ones! And if they are just awkward ones and you end up not liking the guy, then ditch him and move on to another one. Plus, it's not just you who'll be talking on a date, he'll have to talk too!