LoveSales - Find and save products you love, get alerted when they go on sale.
Gift Hero - The best wish list ever
TrackIf - Alerts you if the price of your favorite products drop
Giftwhale - Giftwhale allows you to create personalised wish lists online.
GiftBuster - Wish list registry & shopping list app
Lootr.com - Lootr - Your favorite amazon price tracker. Saving you from paying full price.