WorldNet
The WorldNet covers all electronic/technological forms of communication, from email to full Virtual Reality chat/meeting worlds and games.
Since the WorldNet was created and developed with the funding of the daedra lord Agemnos, most of the fallen gods and other Immortals will avoid using it, preferring enchanted obsidian mirrors (see Communication via Magic below).
Communication via Magic
The most common magical communication device it the "magic mirror." A Conjuration and Illusion spell, bound with an Enchantment field to an object with a reflective surface is used to create an audio/visual link across space.
One of the oldest forms of this magic mirror (and the type favored by the aedra and daedra as a means of secure communication) is obsidian mirrors used at both ends of the communications link.
Similar effects created with Divination/Scrying magic, but the results could be unreliable.
Psionic communication
Telepathy is the primary psionic discipline of communication. Most psis have some level of telepathy, at least enough to be able to safely enter (or be brought) into a gestalt (unified consciousness) with another telepath (or teep).
There are drugs, like Shimmer, that enhance telepathy by chemical/bio-chemical/alchemical means.
Telepathic abilities are enhanced by skin-to-skin contact, and most strong teeps will instantly form a psychic link with anyone they touch, causing a rapid exchange of surface thoughts and feelings between the teep and the subject. Because of this, teeps tend to avoid physical contact with mundanes, who don't have the psychic defenses to shield their thoughts from the bond.
A gestalt with a person that has no psionic ability is avoided at all costs. The mundane does not have the ability to extricate their minds from the link and the teep is not able to cut the link without the mundane's help.
Sources: magic, psionics, WorldNet, email conversation with RavenB, August 2010
