1. A method of facilitating trading, comprising: at a computer, storing a plurality of sets of conditional rules in a memory, wherein each set of conditional rules defines a discovery strategy and an action strategy, the discovery strategy specifying parameters for computer-implemented logic that determines whether to obtain a price quotation for at least one of a plurality of markets and indicates at least one procedure for obtaining the price quotation, and the action strategy specifying order processing parameters, wherein each set of conditional rules is implemented in a computer-executable order-handling program, and wherein execution of the order-handling program includes automatically routing an order to at least one of a plurality of markets in accordance with the selected set of conditional rules; at a computer, receiving a trader selection of a set of conditional rules from the plurality of sets of conditional rules; at a computer, receiving an order for processing in accordance with the selected set of conditional rules; at a computer, receiving information that is applied to the selected set of conditional rules to determine at least one of the plurality of markets to which to route the order; and at a computer, executing the order-handling program configured with the selected set of conditional rules to route the order to the at least one of the plurality of markets in accordance with the set of conditional rules.