Similar to D. Brent, I enjoy using scanning apps when shopping for the holidays or anytime, for that matter. With these apps, you can scan barcodes and read up on reviews and look for the best prices on the net.
Since I'm a big fan of Amazon, I use the Amazon Mobile app on my Droid. When I'm shopping at stores, I can scan the barcodes and do some quick price comparisons and see what others have to say about the products I'm interested in purchasing. When I'm at home, I can simply type and search for items, too. When going on impulse, you can buy products straight through the app.
Another useful shopping app is ShopSavvy, which also allows you to scan products or type and search. If you open a ShopSavvy account, they can help customize your shopping needs and it also provides local listings and allows for connecting with other ShopSavvy users.
Both apps are free and available for Android and iPhone users.
Happy Shopping to all!