There are several ways to do this, however Giz was kind enough to round up 8 software solutions for you. There is the obvious method, the one that guarantees your ringtones will remain with any future iPhone updates, and that is to just go buy them from the iTunes store.

Past that there are a couple manual methods, and there are a few software methods. Some of them require your iPhone be JailBroken beforehand but there are some that don’t. So without further ado here’s the list:

JailBreak:

SSH in and do a manual file transfer of any song the iPhones iPod part will play into the /library/ringtones directory. Sounds simple enough, but I am counting it as one of the manual methods.

iBrickr, it’s a program for Windows that not only places them in the proper location, but will transcode most audio formats into the required format for you.

iFuntastic is the same as the manual method, its just SSH in and put them in the library, but apparently it makes it into a drag and drop interface, its for the Mac though.

Sendsong works on your iPhone and allows you to use any song from your iPod library, and it moves it into the ringtones directory for you. Its available through AppTapp.

Sans JailBreak:

The second manual method is to still use iTunes, just change the file extension of any .AAC track to the file extension of the ringtones, import into iTunes, and sync.

Rogue Ameoba’s MakeiPhoneRingtone is for the Mac and much like iFuntastic for the SSH hack, this app just does the file extension change and import for you, but with a drag and drop interface.

iToner is for the Mac and is the only one of these options, other than buying the ringtone from iTunes, that costs money. No word on how it does what it does, but it works and it costs $15, so if you want software support and updates when this app quits working, consider whether you’ll make 15 ringtones or more and then buy this app.

iPhoneRingToneMaker is for Windows works its magic in the background as well, but has an audio file editor so you can make just a certain portion into the ringtone.

So, there are several free options, and a couple that cost money, there are several factors that go into choosing which one of these methods to use, so I am not going to say which one I would use, partly because I don’t have an iPhone, partly because I’d try all the free ones until I came upon one I felt comfortable with, and then if I didn’t, I’d just pay up. Anyways, good luck with whichever option you choose.

How to: 8 Ways to Get Ringtones Onto Your iPhone [via Gizmodo]