Is there anyway to make a song you downloaded onto your phone into a ringtone?

i have one of those new Krazer phones and i downloaded a song onto it, thinking i could have it be a ringtone. is there any way to do this without buying a new one?

Is there anyway to make a song you downloaded onto your phone into a ringtone?
i'm not sure how this works,but my friend makes his own ringtones.if you have a wire to run from your cellphone to your computer,go to download.com and get wavepad software.you can keep whatever part of the song you want and then put it in your phone as a ringtone.i use the wavepad to shorten songs for movie menus,it works great and it's free.