How can I type foreign language characters?

Mac OS X 
 Courtesy of Indiana University’s Knowledgebase, here are instructions for typing foreign language characters in Mac OS X. This includes various kinds of accents, the tilde and upside down question mark. 
 
 http://kb.iu.edu/data/anhf.html 	 http://french.about.com/library/bl_faq_accents-mac.htm 	 How to type Degree Temperature Symbol in Mac OS X 
 
 Windows 
 There are various ways to type foreign language characters in Windows. Switching to the international keyboard layout helps with typing accented characters quickly: 
 http://french.about.com/library/bl_faq_accents.htm