Want a new ringtone on your iPhone but not willing to spend a couple of bucks for it? Check out Gizmodo - they have listed eight ways to get free ringtones on your iPhone.
Here's a short snip:
• iTunes Music Store: You can manually place AAC files into the correct iTunes Ringtones folder as long as it has the right file extension. Works with purchased iTunes songs or songs you've converted to AAC format. [JoeMaller]
• Rogue Ameoba's MakeiPhoneRingtone (Mac): This takes advantage of the iTunes 7.4 and iTunes 7.4.1 ringtone file compatibility workaround to get the Ringtones show up in iTunes. All you have to do is drop in an AAC file, which can be one of your songs purchased from iTunes. [MakeiPhoneRingtone]
• iToner (Mac): Copies ringtones to your iPhone, bypassing iTunes, should be guaranteed to work with future iPhone updates. Costs $15. [iToner]