Actually you can create iPhone ringtone with full length of song (over 30 seconds) using iTunes. Please be aware that these instruction is base on the iTunes 8.0.2. I never try it out with the latest iTunes (8.1 version). You can try these same instruction on iTunes 8.1 and see if it works or not. However these instruction is works with both jailbroken and unjailbroken (original) iPhone and iPod Touch. If you interested to create ringtone only for 30 seconds using iRinger you may read my post here.

Step 1: Launch your iTunes 8.0.2 and select your favourite songs. For Example i'm already select "I Don't Love You" songs.

Step 2: Right click on the desired songs and the dialog box will pop up on the screen. Select "Create ACC Version" and wait for a while for your iTunes convert it to ACC file format. Once complete you will see the second songs with the same title and info but different file format. (Second Picture). Please note that the original songs is in the MP3 format. You have to convert it first to ACC format. If your songs is already in ACC format you don't need to convert it again. Just proceed to the next step.

Step 3: Right click on the second songs which is in the ACC format. The dialog box will pop up and select "Get Info" for information of this songs.

Step 4
: The dialog box will pop up and shows all the information about this songs. Look out at the bottom of the dialog box info. You should note the info about "Where:C:\Document&Settings\hp\My Documents\My Music\iTunes\iTunes Music\My Chemical Romance\Unkown Album\I Dont Love You.m4a". Find and locate this "I Dont Love You.m4a" file follow by directory above.

Step 5: Before your rename it. You have to do some setting on your windows. Go to menu on your top left and select "Tools" and select "Folder Options" and select "View". Go to "Hide extensions for known files types" option and make sure it an unmarked/unchecked condition. This setup is to ensure that you'll be able to rename or change the name of file extension. If this option is already been setup, ignore this step and proceed to the next step.

Step 6: Create a "new folder" and rename it and put it on your desktop. Copy the located file name "I Dont Love You.m4a" and save it into your "new folder" on desktop. Right click on the file name "I Dont Love You.m4a" and dialog box will pop up and select "Rename". Just rename/change the file extension to .m4r and click "Yes" if you're required to confirm it. Once complete, you'll see the icon is change and the file name is become like "I Dont Love You.m4r"

Transfer .m4r file to iPhone Using Disk Aid

Please take a note that you can't be able sync your new ringtone and installed it to your iPhone via iTunes. However transfer ringtone file using Disk Aid is pretty easy. DiskAid is a freeware that lets you transfer files between iPhone / iPod Touch and computer and enables your iPhone as USB thumb drive or external HardDisk. DiskAid is free to download. You can download it directly from here. You can checkout my post here for further details about Disk Aid.

Step 6: Connect your iPhone to PC using USB cable. Launch Disk Aid and go to bottom left and click "Root Folder". You're required to confirm it, just select "OK" to confirm.

Step 7: The ringtone file that we would like to copy should be save it at /Root/Library/Ringtones directory. Once you're at "Ringtones" directory just click at menu "Copy File To Device". You'll be required to select file that you want to copy, just locate "I Dont Love You.m4r" file where you just saved it at "new folder".

Step 8: Once your complete, you ringtone file is saved in your iPhone. Close your Disk Aid.

Step 9: Just "slide" to unlock your iPhone and Go to "Setting" > "Sounds" > "Ringtone" to check your ringtone. You should see a new favorite ringtone just added into your "Standard" ringtone section.