Twype - use Twitter to update your Skype presence
tweetafile - upload a file, which will send a direct message to your Twitter friend with a link to view or download the file
TwitterSync - Another way to sync your latest tweet with your Facebook status. There is a Facebook app to add a Twitter widget to your profile, you can also set it to update your tweets as your Facebook status.
I kind of see this as spam, it would be good if you could “choose” to show a tweet in your Facebook status, instead of all tweets by default showing up in your Facebook status.
The Big Juicy Twitter Guide