Attributional biases typically take the form of actor/observer differences: people involved in an action (actors) view things differently from people not involved (observers). These discrepancies are often caused by asymmetries in availability (frequently called "salience" in this context). For example, the behavior of an actor is easier to remember (and therefore more available for later consideration) than the setting in which he found himself; and a person's own inner turmoil is more available to himself than it is to someone else. As a result, our judgments of attribution are often distorted along those lines.
In some experiments, for example, subjects were shown only one side of a conversation or were able to see the face of only one of the conversational participants. Whomever the subjects had a better view of were judged by them as being more important and more influential, and as having had a greater role in the conversation.
Perhaps the best known attributional bias is the fundamental attribution error.