Usher's ubiquitous hit, 'OMG,' noted on many end-of-year lists as a top tune of 2010, is causing some controversy. The R&B singer is reportedly accused of stealing the hook from a song used in a 2003 episode of 'The Simpsons' and remixing it into the version that appears in his current smash.

On Usher's track, written and produced by Will.i.am, he sings, "Honey got a booty like pow, pow, pow/ Honey got some boo---- like wow, oh wow." In 'The Simpsons' episode, titled 'Dude, Where's My Ranch?' Homer Simpson belts out a holiday tune, singing, "Christmas in December, wow, wow, wow/ Give me tons of presents, now, now, now."

While both songs are similar in lyrics and composition, it is hard to tell if 'OMG' truly reflects the "borrowed" lines Usher is being accused of jacking. Radio jocks at Y101.7 in Jackson, Miss., made the startling discovery and created a mash-up of the songs, released via YouTube. Producers of 'The Simpsons' have yet to release a statement regarding the issue.

Usher is in hot water elsewhere for another plagiarism charge. Wadena Pyatt claims that the 'Raymond v. Raymond' creator and singer Alicia Keys stole the 2004 hit 'Caught Up' from her. In the lawsuit, Pyatt reveals that she was signed to MBK Entertainment in 2003, the same label Keys' former manager, Jeff Robinson owns. During that time, Pyatt says she wrote the song for inclusion on her debut LP. Pyatt then heard 'Caught Up' on Usher's 'Confessions' album, yet was not listed as a songwriter. She's demanding payment for profits received from sales of the track.

Listen to Usher's 'OMG' and 'The Simpsons' Mash-up