... what? do you mean, casting a circle and calling forth [if he wasn't fictional] Dumbledore from England to you in, say, the states? no. summoning is used when something from a non physical plain is needed for assistance [dragons, demons, ghosts, faeries, so on]
it's like teleportation, kind of a grey area, i'm pretty sure it can't be done, i have a friend who claims she did, but she lives in her own fantasy world. [i mean, i have an overactive imagination, but her's is out of control] and people have made claims of such things, but without proof, i'm not inclined to believe. there is a way of astrally projecting to visit someone on this plain, but i'd personally go with a letter by means of communication over distances, i like the whole mail thing, very old fashioned and fun. mind you slow, it has a more human touch.