Ok, so myself like most I'm sure wanted to use a song as a ringtone on my iPhone. The phone will not let you do this, so after tinkering around for the past 3 hours trying to figure it out I was successful. I figured I'd better write up a quick How-To on it, there's quite a few steps.
This is for Windows XP btw:
Ok, first just to avoid future problems there are some things you need to check on your computer so you don't get a headache. Go to your iTunes, go up to Edit, go to Preferences, and make sure the box that says Ringtones is checked. This will give you a Ringtones folder in your Music Library. Ok, the other thing you need to check is to see if your file name extensions are visible. Go to your Control Panel in the Start Menu, go to Appearances and Themes, go to Folder Options and go to View and make sure that the box next to "Hide Exentions for Known File Types" is UNCHECKED! This will let you change the file type of your song when we get to that point.
Ok, the song you pick to be your ringtone, find the exact starting point at which your want your ringtone to begin and remember the time, right click the song and go to Get Info, go to Options, check the 2 boxes that says Start Time and Stop Time, put the time in that you want your ringtone to begin and then put the stop time in at 15 or 30 seconds later than your start time, click OK. Right click the song again, go to Create AAC Version, it should take a few seconds and you will see a duplicate of your song, but the length will be your ringtone length that you chopped it too, right click your new ringtone song, go to Show in Windows Explorer, it should be highlighted, click it again to change the file name extention from .m4a to .m4r, it should prompt you saying that changing the file may make it unusable, are you sure? Hit yes, it will change. Now, double click in that same window to play the file, it should play just the length you edited and should appear automatically in your Ringtones folder. Go back to your library, delete the short edited version you made as it is now unusable as a music file, go to your original song right above it, go to Get Info, and uncheck the Start Time and Stop Time boxes so that next time you want to listen to the song you'll get the whole song like your supposed to. Now, the new ringtones you made should already be in the Ringtones file when you select your iPhone in iTunes, go to Ringtones on your iPhone through iTunes, check the box that says Sync Ringtones and pick either All Ringtones or Selected Ringtones. If you choose Selected Ringtones, they will only appear if they are checked in the Ringtones folder in your Library. Hit Sync and you're done, free ringtones w/out editing software on your iPhone just the way you want them. To apply them go to Settings>Sounds>Ringtone>and there should be a list right there with all your songs labeled Custom Ringtones. I hope this is helpful, it took me forever seeing as all the how-to's online were really vague or steps were missing. Enjoy.