Notice! This mod is apparently broken at the moment, because of changes made by Facebook. I am looking in to this, and will keep you updated. - Lex Link to ModFacebook & Twitter Sharer Mod 2.0
With Optional Database Settings Uninstaller Built In
By Aleksi "Lex" Kilpinen
COMPATIBLE WITH SMF 2.0 RC4 -> SMF 2.0
Support for Curve and Core built in, will support most themes based on either one,
and any theme that doesn't have it's own Display.template and uses Curve's or Core's Display.template instead.
This mod adds easily customizable, and translatable Facebook Share and Twitter Tweet -buttons to topic view.
You can customize the FB button text, by editing the language string
$txt['facebooksharer_button'] in Modifications.{your language}.php
English and Finnish strings included in the package.
Notice!Upon installation this mod will add two database columns named facebooksharer_board_enable and twittersharer_board_enable in to the boards table of your forums database. These columns hold the boardsettings for this mod.
SharerWithDBUninstall.zip version of the package, upon uninstallation will remove the same columns,
so after uninstalling, the settings for this mod will not be retained.
SharerNoDBUninstall.zip version of the package, upon uninstallation will not remove the same columns,
so after uninstalling, the settings for this mod will be retained.
Also, a separate uninstallsharer.php available, that removes the columns if you should need it.
Release History- 06.07.2011, Released 2.0 Adding Twitter support

Removed 1.* versions from modsite.
- 06.07.2011, Fixed fatal error upon install, in case settings were already in the DB.
Changed the board setting default value to be activated.
- 05.07.2011, Added 2.0 Final compatibility.
- 12.02.2011, Added RC5 compatibility.
- 04.02.2011, Found the actual reason for Core failing in 1.0 - Reverted changes in 1.1, and fixed the error from 1.0. Also fixed typos.
- 03.02.2011, 1.1 Fixed Core compatibility, at the same time making it more prone to fail - will see later if there's a better way to do this.
- 06.11.2010, Submitted 1.0 for the Cust.Site.
Licence:
User submitted translations for version 2.0 (Facebook and Twitter):
//Begin Sharer Mod by Lex - Translated By Darkness
$txt['sharer_allow'] = 'Permitir tópicos ser compartilhado para o Facebook ou Twitter? (Configurações Master)';
$txt['tweetsharer_board_enable'] = 'Permitir tópicos a serem partilhados no Twitter deste fórum';
$txt['facebooksharer_board_enable'] = 'Permitir tópicos a serem partilhados no Facebook deste fórum';
$txt['tweetsharer_board_enable_desc'] = 'Esta opção permite que as pessoas usem o Sharer mod para o Twitter no quadro selecionado.';
$txt['facebooksharer_board_enable_desc'] = 'Esta opção permite que as pessoas usem o Sharer mod para o Facebook no conselho selecionado.';
$txt['facebooksharer_button'] = 'Compartilhar';
//End Sharer Mod by Lex - Translated By Darkness
//Begin Sharer Mod by Lex
$txt['sharer_allow'] = 'Consenti argomenti da condividere su Facebook o Twitter? (Impostazione Principale)';
$txt['tweetsharer_board_enable'] = 'Consenti argomenti da condividere su Twitter da questo forum';
$txt['facebooksharer_board_enable'] = 'Consenti argomenti da condividere su Facebook da questo forum';
$txt['tweetsharer_board_enable_desc'] = 'Questa opzione permette alle persone di utilizzare il mod Sharer di Twitter sulla scheda selezionata.';
$txt['facebooksharer_board_enable_desc'] = 'Questa opzione permette alle persone di utilizzare il mod Sharer di Facebook sulla scheda selezionata.';
$txt['facebooksharer_button'] = 'Condividi';
//End Sharer Mod by Lex