My friends and I are Karaoke junkies. At almost every get together the preprogrammed mics filled with thousands of songs come out and with enough booze in our systems; we get to sangin'. This brilliant iPhone application called iLyric Player streams lyrics in sync with the song playing. It even lets you rearrange the timing for group sing-a-longs.
the first time i karaoked in Osaka to Welcome To the Jungle at 4am... i blew my voice and couldn't talk for three days afterwards.