Cellphone Ringtones

Find an MP3 or MIDI file
Start with the MIDI or MP3 file that you want to have as a ringtone. You can rip an MP3 from a CD using FreeRIP, an useful little piece of freeware. You can download MP3s for free below.

Editing MP3 files
If your MP3 is an entire full length song, you should edit your ringtone length to around 20 seconds or less. Many phones will not play an entire MP3 file, and you can waste phone memory and only hear the first part if you do not edit the MP3. Here's where downloading Audacity comes in handy. Audacity is a free, open source, cross-platform sound editor. To edit MP3s, you will also need to download the mp3 compression library, lame_enc.dll, file here to your hard drive.

Setting Up Audacity Audio Editor
Run Audacity, go to the Audacity/Preferences menu, and click the Find Library button near the bottom of the screen. Navigate to the LAME Library you just saved on your hard drive, and select it. I recommend a bit rate of 128 Kbps. Though 96Kbps is still good and a lower bit rate will save memory on your phone, but you'll get lower quality sound.

If you don't want to download and setup Audacity, Mobile17 is a site that let's you upload an MP3, trim it, and email it or download it from their site. They are free, but there is a sign up process.

MIDI Files
MIDI files are easy because they are already very small and usually do not require editing. There are many sites on the web where you can download MIDI files, a good one is harmonicMedia. Transferring them to your phone is the same as MP3 files.

Record Directly on Your Phone
You can even record the audio on your phone receiver itself and save it. You just have to push enough buttons on your phones to figure out how. It's usually in a Tools menu or Sound menu. This technique may result in lower quality audio but can get you experimenting with unique and creative ringtones.