The case is the only visible element of a computer from the outside. So you need to choose it at your taste!
You must also take care of its characteristics, but nowadays, all manufacturers create good cases, more practical and evacuating a maximum heat. You have still some choices to make.
As in all domains, in computer science there is a huge gap between the "newbies" who buy a computer in supermarkets, and the experts who will choose each component one by one. 
However, many shops and Web merchants offer to assemble your machine for $30 to $60. It allows you to build your custom PC. But build it yourself is even not so difficult as you may think. Each piece fits generally only in the correct location. 
Finally, your machine can be much more efficient and powerful for the same price as the mounted computers.
Sometimes an image is more than one thousand words... This schema shows how you read a DVD when you illegally download it, and when you stupidly pay to see ads!
Here we are on 1 January 2010, this site now exists for 2 years. Since we have seen the appearance of processors with multiple cores, phones with more and more features...
On the Web, the fashion in sites design was sober and clean, today they become again heavier and flashing. Social networks have lost some appeal and the public returned to the classic information sites.
Google has expanded its system of spying on all Internet sites using its advertising.
For a TV program a camera was hidden in the ladies room. The people on the TV set can speak and make some fart noise in the toilettes with a speaker.
Watch the reactions of the other women...
