What is the difference between Ph.D, D.Sc, D.Litt, etc.? Is there any difference between Ph.D, D.Sc, D.Litt and the similar degrees?
The meaning of these degrees vary by country. In some countries (especially in Europe), PhD is the "basic" degree. It's the one you get out of graduate school. D. Litt (aka. Doctor of Letters) and D.Sc (Doctor of Science) are the highest conferred degrees. You need sustained achievement at the top before these are awarded. Here's a quote from the Wikipedia article on D. Litt:


  The Litt.D. degree is awarded to candidates whose record of published work and research shows conspicuous ability and originality and constitutes a distinguished and sustained achievement. University committee and board approval is required, and candidates must provide documented mastery of a particular area or field. The degree may also be awarded honoris causa to such individuals as the university or the learned body in question deems worthy of this highest academic award.


D.Sc is similar, except it's for the sciences as opposed to social sciences. Again, see the Wikipedia article, except there're many non-European countries who take D.Sc to be effectively equivalent to PhD.