Useful web sites

Some more useful sites that deserve to be better known than they are, in no particular order:

The phone book online (AKA electronic directory enquiries):
http://www.thephonebook.bt.com/

Royal Mail Service Portal (postal prices, regulations, etc.)
http://www.royalmail.com/portal/rm

DVD Price Check - checks lots of sites for the best prices.
http://www.dvdpricecheck.co.uk/

The Online Books Page - links to tens of thousands of books that are on line
http://digital.library.upenn.edu/books/index.html

Biodidac - a wonderful collection of drawings etc. for biology
http://biodidac.bio.uottawa.ca/