I think Summer told me about Myxer a bit back and I finally had a chance to check it out over the weekend. It is another simple and free website that lets you create a ringtone and send it to yourself. Myxer also as an impressive catalog of mostly free ringtones and wallpapers but some of them are premium so watch out.
It may not have the complexity of services such as Zedge or Aukido but it is definitely worth checking out. It does have some unique features such as a Firefox and IE extension for creating a wallpaper out of anything. You do have to register for free to get some of these features to work but registration is free.
Check it out at www.myxer.com and let us know what you think!