Everyone loves sharing stuff online. Whether it's music, videos or simple photos, we find the human impulse to share hard to resist. And if you mix this natural tendency – especially regarding music – and a popular social network such as Twitter, you end up with a bunch of mashups and online tools that enable you to share your music on Twitter in a very easy way. Here are some of them:

• TwittyTunes – lets you post the song you're currently playing to Twitter. You can select specifically which songs you want to share. Requires the FoxyTunes Firefox extension to work.
• Twisten – created by the same developers of Grooveshark - and therefore featuring a large music collection - this music sharing app updates your Twitter profile with with the song you're listening to, plus some links with information about the artist.
• Tweetj – add a #tweetj tag to your tweets and they'll be automatically added to a public playlist with the music you listen to. These lists let you to discover new music and include links to buy those MP3 on Amazon.
• Blip.fm – this full-featured social community built around music enables you to share your favorite songs and bands in other social networks, including Twitter.
• LastFMLoveTweet – sign up for this mashup and any song you 'love' on last.fm will automatically posted to your Twitter account with the artist's name and a link for your followers to listen to it as well.