Not sure if this officially belongs here or not but hey, worst thing that happens is it gets moved. (Or I offend someone and they hunt down my family and remove bits of skin one inch at a time.... I suppose that is worse than the post being moved...but I digress) There are quite a few sound boards out there that let you save certain clips as ringtones or notifications as well. (I made my first one this month! *plug coming* It's a Monty Python Soundboard) Basically it copies said file to your SD card and then has the mediastore rescan the card for new files. If the files are in a location with the title of "ringtones" or "notifications" they will show up in said selections. So if you don't have one of those programs, simply place the files into the correct directory and then unmount and remount your sdcard to make it rescan.
My ringtones are in:
/sdcard/MEDIA/audio/notifications
/sdcard/MEDIA/audio/ringtones
Where sdcard its your SD card root...