Urgent, Its about blogging?

[Jake]

Urgent random thought?

Really, if you don't have a burning desire to share your knowledge about some subject you have passion or at least strong interest in, the odds are you won't remain motivated enough to build up something worthwhile, there are far too many half baked sites getting less than 10 visitors a day.
The internet is big enough to allow a site on just about any subject succeed, if it is one of the best in it's field, picking a subject that people spend money on increases your chances of making money from paid advertising, etc.

There are plenty of discussion forums or article directories where you can contribute without having to manage a site.