If you're looking for a new way to spice up your phone's tonos para celular, there are several options available. Some are free and some cost money.

The Center for Biological Diversity has started offering the world's most endangered critters as free ringtones. They include calls of a Beluga whale, Blue-throated macaw and Boreal owl, among others.

A Slacker Radio Tones App on Verizon

If you subscribe to Slacker, you can get access to a new app that adds a lot of great ringtones and ringback tones. It is only available for iPhones and iPods, however. It's an in-app purchase that costs $2 per month, but you can get a lot of new sounds for your device with it.

Loud Siren Ringtones

Whether you like to rock out or you just want to add some cool ringtones to your device, this is the app for you! These ringtones will give you the energy boost you need to keep your phone going.

Some of them are even made to look pretty cool. They're designed to make your phone's ringer look like it's from a rock band.