Connexions Direct
Offers advice on education, careers, housing, money, health and relationships for 13-19 year olds in the UK. Includes web chat, telephone and call-back services.
http://www.connexions-direct.com/
Covenant House: Nineline
A 24-hour nationwide toll free hotline that provides immediate crisis intervention to young people and refers callers to help in their own communities. (US only)
http://www.covenanthouse.org/nineline/index.html
SafeTeens
Provides information about staying safe online. Includes articles about protecting your privacy, and links to other online safety resources.
http://www.safeteens.com/