Why would you need a wearable?

Attributes that a wearable needs to have...

Convenience

Users want to have access to the information that they want and need when it is convenient for them. Internet enabled phones is one recent example of this.

Ease of Use

Users are willing to put up with some inconvenience to get the information that they want, but this level is very low. The Apple Newton is a great example. It is basically a larger version of the PDA, except it wasn't as easy to use.

Mobility

Users will not use a luggable computer on a daily basis.

Screen Size

Who wouldn't want a cell phone sized device with the screen area and resolution of a laptop?

Privacy

The ability to work on what you want when you want it without having prying eyes is vital to some and at least useful to most. Examples: Reading a sensitive email while on the T; working on a business plan for the $50k; IM'ing with friend while in class.