I use my cell phone as my alarm clock. This has the added benefit of ensuring that I charge my phone pretty much every night. Dana recently said she was tired of the same old alarm noise in the morning, and I realized it was time to get a couple of new ringtones.
Several months ago I discovered, through Google and some trial and error, how to make a ringtone from an MP3 and transfer it to my phone (Motorola v600). The trickiest part, in my opinion, is editing the music to a short section that sounds natural when it repeats. I import the MP3 to Garageband, which converts it to AIFF, edit it there, then send it back to iTunes and have iTunes re-encode it to MP3, at a sample rate my phone will like. Then send it to the phone over Bluetooth, and it's done.
At the time I did this with music from Fantasmic, and loved the result. So last weekend I picked a few more, and I now have ringtones for the Overture from Candide, Doctor Who, Deep Space Nine, the Price is Right, and, probably my favorite, Linus & Lucy (the Peanuts theme).
I would post samples, but I'm pretty sure that would be breaking some copyright rules. I don't have a problem arguing that what I've done is fair use of music I own, but distribution would be different.
Anyway, it was a fun project. I'm overwhelmed, sometimes, with all the fun things one COULD do with music, photos, and movies (and iLife makes much of it easy), so it's nice to actually sit down and do a project like this.