9. A non-transitory computer-readable medium having instructions recorded thereon for transmitting a recommendation, the instructions comprising: instructions for adding a first friend to a user's network of friends in a social network; instructions for receiving a first rating from the first friend regarding a first product or service; instructions for receiving a first indication from the user that the user agrees with the first friend's rating of the first product or service; instructions for adding a second friend to the user's network of friends; instructions for receiving a second rating from the second friend regarding a second product or service; instructions for receiving a second indication from the user that the user disagrees with the second friend's rating of the product or service; instructions for computing a trust values for each of the first friend and the second friend based on trust values associated with each of the first friend and the second friend in the social network; instructions for creating a data set representing the first friend as a first node and the second friend as a second node and connections between the first node, the second node, and the user as a plurality of directional edges, each having an associated expression of trust value, wherein: a first directional edge of the plurality of directional edges represents the connection between the first node and the user and has a positive expression of trust value based on the first indication from the user that the user agrees with the first friend's rating of the first product or service, a second directional edge of the plurality of directional edges; represents the connection between the second node and the user and has a negative expression of trust value based on the second indication from the user that the user disagrees with the second friend's rating of the second product or service, and, the computed trust values for each of the first friend and the second friend being greater than or equal to a threshold associated with a minimum level of trust in the social network; and instructions for transmitting, to the user, a recommendation for a third product or service based on the positive expression of trust associated with the friend and information that the first friend rated the third product or service positively.
11. The non-transitory computer-readable medium of claim 9 , wherein the non-transitory computer-readable medium further comprises instructions for receiving input from the user's friends in the social network, the input representing ratings of a plurality of products and services and expressing trust in friends of the social network to provide a rating.