what format are ringtones for sprint LG RUMOR phones?

i just recently purchased a sprint LG rumor, i'm trying to make a song on my media card a ringtone but that is not an option. HELP!!

you need to make a smaller version, phones don't allow that because sprint wants you to buy ringtones from them,
if you have internet, the site

Ventones
lets you make ringtones from mp3 files,
and it does work on my sprint muziq phone.
don't know about the rumor though