Most of those who attended some marketing oriented school (myself included) had to become familiar with the concept of brainstorming, at one point or another.

The Marketing Dictionary defines brainstorming as:

Idea-generating technique is often used in advertising by a creative team to spark creativity. The team will gather in a group and throw out spontaneous ideas without evaluation until they hit upon something that may be useful. In this process nothing is too silly or farfetched to be suggested. The process helps to make the leap from the visualization of an idea to the concrete words and pictures that will actually form the basis of the advertising campaign.

This is certainly a narrow definition but one can certainly extend brainstorming out of the marketing world into any idea/feature/product generation process. A better definition and explanation of the concept and process can be found in the Small Business Encyclopedia:

Brainstorming is a group problem-solving technique that is intended to help members develop innovative new approaches to a problem in an unthreatening environment. First developed by A.F. Osborne in 1941, brainstorming in its most basic form involves stimulating all the members of a group to express a variety of ideas, which are built upon and recorded for future reference. Critical judgment of the ideas is reserved until later in the process, when the ideas are evaluated, combined, improved, and changed until the group reaches a final resolution of the problem. Brainstorming can be particularly useful in providing creative solutions to problems that have defied traditional problem-solving methods, as well as in such applications as new product development.

There are three critical factors that determine the success of a brainstorming effort. First, the group must strive to produce a large quantity of ideas, as this increases the likelihood that they will happen upon the best possible solution. Second, the group must be certain to withhold judgement of the ideas as they are expressed, since the negative thinking of one group member can make others less willing to participate and thus derail the whole process. Third, the group leader must create a positive environment for the brainstorming session and channel the creative energies of all the members in the same direction.

I have also searched a little bit around Slideshare and found the following presentation:

Some students/companies are developing technological aids to improve the brainstorming process. One of them is shown in the following video: