How is that difficult? Seriously, it's as easy as eating pie.
I personally use audacity to edit the clip to where I want it, but you can use whatever method you want.
Of course, you can also pay Apple money for them to make the ringtone for you. That's limited to what's available and you can't use any obscure song you've got.
1. First get the song you want to make the ringtone from.
2. Open it with quicktime pro (or any other editor)
3. Cust out the section you want as the ringtone and save it as a new mp3.
4. Import it into iTunes
5. in iTunes go into
Preferences > Advanced > Importing
Set to Import using: AAC encoder 128Kbps
And/OR:
6. Right click on the file you want as a ringtone and select:
Convert selection to AAC
Your file will now be converted to an AAC file. (appears in iTunes under your original file) - call it a different name, so as not to confuse, ie: instead of Song.xxx, call it Song1.xxx
7. Right click on the new file, click on show in finder (or open folder on windows)
8. You will now see your AAC file, all you have to do now is change the file extension from .m4a to .m4r
9. Drag the file out of the folder to the desktop, then drop it back into itunes. (Hover over your 'Ringtones' in the left menu list of iTunes, or it will just go into your main library)!
Sync with your iPhone. Done.
Eating pie is A LOT easier than that...
I am usally down for steps like that to get something nice or special, not something i was able to do in 2 seconds with my Sony Ericsson WALKMAN series, or my previous phone. Just saying, it would be nice if it was a lot easier.