I disagree. Maybe flamebait, but I think 100% is usually either a silly goal, or a good start. 100% for a complex project is basically impossible to achieve (and assumes every area of the code is as important as the next), and for a lot of code 100% is nothing. Consider a function that divides to arguments and returns the result. I can pass in div(2,2). There, done. 100% coverage.

[edit] I forgot to mention what value I do think it has. On teams that I'm on I always say I frankly don't care what the number is, as long as it's going up and not down.