This technique especially helps novice users quickly grasp how your application works. Folders are a classic software metaphor. People file things in folders in the real world, so they immediately understand the idea of putting data into folders on a computer.

iPhone OS users enjoy a heightened sense of direct manipulation because of the Multi-Touch interface. Using gestures, people feel a greater affinity for, and sense of control over, the objects they see on screen, because they do not use any intermediate device (such as a mouse) to manipulate them.

An iPhone application is better than a person at remembering lists of options, commands, data, and so on. Take advantage of this by presenting choices or options in list form, so users can easily scan them and make a choice. Keeping text input to a minimum frees users from having to spend a lot of time typing and frees your application from having to perform a lot of error checking. Presenting choices to the user, instead of asking for more open-ended input, also allows them to concentrate on accomplishing tasks with your application, instead of remembering how to operate it.

Your application should respond to every user action with some visible change.

Keep actions simple and straightforward so users can easily understand and remember them

Whenever possible, use standard controls and behaviors that users are already familiar with.

appearance has a strong impact on functionality: An application that appears cluttered or illogical is hard to understand and use.

Aesthetic integrity is not a measure of how beautiful your application is. It’s a measure of how well the appearance of your application integrates with its function. For example, a productivity application should keep decorative elements subtle and in the background, while giving prominence to the task by providing standard controls and behaviors.

An immersive application is at the other end of the spectrum, and users expect a beautiful appearance that promises fun and encourages discovery.

appearance still needs to integrate with the task.

When wealth is talked about in this context, it is often described as a pie. "You can't make the pie larger," say politicians. When you're talking about the amount of money in one family's bank account, or the amount available to a government from one year's tax revenue, this is true. If one person gets more, someone else has to get less.I can remember believing, as a child, that if a few rich people had all the money, it left less for everyone else. Many people seem to continue to believe something like this well into adulthood. This fallacy is usually there in the background when you hear someone talking about how x percent of the population have y percent of the wealth. If you plan to start a startup, then whether you realize it or not, you're planning to disprove the Pie Fallacy.What leads people astray here is the abstraction of money. Money is not wealth. It's just something we use to move wealth around. So although there may be, in certain specific moments (like your family, this month) a fixed amount of money available to trade with other people for things you want, there is not a fixed amount of wealth in the world. You can make more wealth. Wealth has been getting created and destroyed (but on balance, created) for all of human history.Suppose you own a beat-up old car. Instead of sitting on your butt next summer, you could spend the time restoring your car to pristine condition. In doing so you create wealth. The world is-- and you specifically are-- one pristine old car the richer. And not just in some metaphorical way. If you sell your car, you'll get more for it.In restoring your old car you have made yourself richer. You haven't made anyone else poorer. So there is obviously not a fixed pie. And in fact, when you look at it this way, you wonder why anyone would think there was.

what parts of the online display-ad ecosystem, estimated by eMarketer to be worth $7.9 billion in 2010, are adding value for publishers or brands, and what parts are preventing the flow of brand dollars into the system.

While some publishers remain wary of Google as both a service provider to publishers as well as a competitor for display-ad dollars, Google's argument is that its motivations are virtuous. As VP-Product Management Susan Wojcicki said last week at the Internet Advertising Bureau's annual meeting, Google makes money when publishers do. That, and the set-up isn't much different from Microsoft, itself a seller of online ads as well as a service provider to publishers.

Any time you have companies talking about their secret algorithms or black boxes, it should raise a red flag, he said. For publishers and advertisers, the question should be: Do they make the whole thing bigger and better?

KT officials said the company is aiming to continue its dominance in the local market by adding live chat video and even Wi-Fi functions to the upcoming devices.

During the period from November last year to Jan. 7, KT sold 220,000 units of 3G iPhones ― a good performance for the carrier.

KT, led by CEO Lee Suk-chae, is targeting to sell 500,000 units of iPhones including the 4G ones by the end of this year, a KT spokesman said.