Search for wish lists at big retailers. Your giftee might have an Amazon wishlist already, and all you need to find it is their email address. This could be a great way to get your sister, friend or boss exactly what they want without havign to ask. Alternatively, if your giftee has recently gotten engaged, married, had a baby, or hosted a housewarming, they probably still have empty items on their registries. Even if they were married months ago, they might still appreciate recieving that cool kitchen gadget they picked out.
Glance through their social networks. Take a peek at any recent links they've posted to Facebook or Twitter to see if there's any good gift ideas. Or go through their StumbleUpon, Digg or Reddit history to find product links they liked or upvoted in the past. And if your giftee uses Pinterest, you've got it made! Find their profile to get dozens and dozens of great gift ideas that they're guaranteed to love.
Do you use the web to help you pick out great gift ideas? Share your sneaky tips in the comments!