Motorola SLVR L7c

Hi everyone, I recently bought a slvr l7c from verizon wireless, and before you ask I don't have a micro SD card. However, I have a usb cable and a copy of motorola phone tools. Is there any possible way to send a custom ringtone to my phone (via CABLE or INTERNET?) without having to pay for it? If someone could guide me through that process I would appreciate it... I just want some cool ringtones without having to buy them.