How to convert .MP3 file to .MID file?

I have the verizon's LG enVtouch phone and in orders to get any ring tones i have to pay for them… But if i can convert some of my songs to MID i think i will be able to play them as a ring tone. If someone can offer some free well working converter that can convert MP3 to MID i will appreciate it. Or also will be thankful if someone can tell me how to get free tones

Suggestion:

You can also text yourself the files by emailing them to yourphonenumber@vzwpix.com- you can then save the file as a ringtone when you receive it