Future Tense for December 27th looks at shopping bots. One of the most sought-after items this holiday season is the Sony PlayStation 2, the powerful game console that's been in short supply. Some of those lucky enough to find PS2s did so with shopping bots, software that crawls through the Web looking for product availability and price. Shopping bots allow consumers to comparison shop and hunt for bargains; they can cover more ground than a human shopper. Carrie Johnson with Forrester Research says bots are beginning to make their presence felt.