Sony Music Entertainment has reached a deal with mSpot to allow mobile users on Sprint, Verizon and AT&T's networks to download and customize selections from the record label's vast library. The tunes can then be edited into ringtones using the mSpot Make-UR-Tones mobile app.

The three other major music labels, EMI, Universal Music and Warner Music, already had agreements with mSpot. Some indie labels also partner with mSpot and the company's library now exceeds 400,000 songs.

To get stared, select a song from mSpot's homepage and then follow the simple steps to select the part of the song you want as your ringtone. Or, download the mobile app and do it all on the go.