SEO and Meta tags

Is there really need for any kind of Meta tags on the websites? It seems that SEO experts keeps pushing website authors to create meta keywords and descriptions. Sometimes they also push Dublin Core and even more detailed meta tags but for as far as I understand this is complete waste of time.
I am not an expert in this field so please correct me if I am wrong but it seems that all major search engine robots ignores meta tags, I am not sure though if they read it in some level but I doubt they do. At least Meta Keywords are nowdays ignored completely.
Second, how about so called “SEO friendly URL’s” is it still relevant having keywords on URL?

For example:
If I have 3 URL’s

  1. index.html?id=123
  2. /archives/123/
  3. /tourism/europe/spain/barcelona/picasso-museum/

Which one of these is the most friendly for robots? Usually it is recommended not to use query strings in URL’s but is this the case still?

If you know answer for my questions please drop me a line…