Add social buttons to your web page... links to explanation and tools

The links below link to explanation and tools that generate code to include in your web pages. Please mind: some of these will not work in locally (on your harddisk) stored files.

Mail links (the most classis form of social stuff):

Example code:
http://www.w3schools.com/tags/tryit.asp?filename=tryhtml_link_mailto2

Add Facebook chat to ASP.NET:
http://www.nuget.org/packages/Facebook

Twitter buttons:
https://twitter.com/about/resources/buttons

Facebook buttons:

For liking:
https://developers.facebook.com/docs/plugins/like-button/

For following:
https://developers.facebook.com/docs/plugins/follow-button/

For sending pages:
https://developers.facebook.com/docs/plugins/send-button/

For sharing pages:
https://developer.linkedin.com/plugins/share-plugin-generator

Skype:

http://www.skype.com/en/features/skype-buttons/

Google:

Google share:
https://developers.google.com/+/web/share/

Foursquare:

Save to Foursquare and like buttons:

https://foursquare.com/about/logos

Button builders (builds for all kinds of social platforms):

http://support.addthis.com/customer/portal/articles/381237-third-party-buttons