Twitter just achieved a holy trinity of snackable multimedia: you could already view Instagram pictures and YouTube (s GOOG) videos within tweets, but now you can also listen to SoundCloud sounds without ever leaving Twitter.com.
If it sounds a little Facebook-ey (s FB), it should -- this, along with the other parts of the 'expanded tweets' announcement, shows Twitter stepping up far more explicitly than before as Facebook's most plausible rival.
