According to BMI, ringtone sales for 2006 were $600 million; $500 million in 2005; $245 million in 2004; and $68 million in 2003.

For the first time, BMI has released a U.S. ringback market estimate. A ringback tone is a music piece that a caller hears when they call another mobile phone. They estimate that for 2007 ringbacks will generate $65 million in revenue.

BMI’s projections are from 520 million individual ringtone purchases, which have been examined for the past 12 quarters. They tracked data from 325 retail stores for the purchase of mobile entertainment in the U.S.

"As we forecasted last year, the ringtone market matured in 2006. The slowdown in ringtone growth, however, was partially offset by the first wave of promising U.S. growth in ringback tones," said BMI Vice President of New Media and Strategic Development, Richard Conlon.

 "We believe that the ringtone market’s growth has leveled off and the novelty phase has ended. We envision increased revenue opportunity in the streaming sectors of the mobile entertainment market, ranging from ringtones to audiovisual cellular phone TV-style offerings."

According to the Yahoo buzz blog searching for ringtones remains solid. Over the last week searches increased 32 percent while searches for free ringtones were up 10 percent.

Here are the current top 10-ringtone searches according to Yahoo.

1.Mosquito Ringtone
2.24 Ringtone
3Cricket Ringtones
4.Christian Ringtones
5.CTU Ringtone
6.WWE Ringtones
7.Crazy Frog Ringtone
8.Country Ringtones
9.Final Fantasy Ringtones
10.Bollywood Ringtones