MobSaver: By text messaging mobsaver, you can instantly compare online vs. retail prices while you're at the store. If you decide to buy online, you no longer have to memorize the titles and hope to still remember them by the time you get home. Simply text mobsaver, sign in when you get home, and you'll see your saved list of items.
TicTap: Search Amazon.com products from a mobile device such as your PDA or smartphone. View prices, reviews and recommendations before purchasing. Use SMS (Short Message Service) to search for Amazon.com products over your mobile device.
Smarter.com: Ever been in a computer or electronics store,and wondered how much money you could save online
Ringfo: compare prices, customer ratings, and more, from any mobile phone
411Sync: 411Sync lets users do searches for prices and many other things.
mShopper: mShopper allows you to do comparative shopping on your smartphone and also offers retailers a mobile web storefront