If you have a number of notes that you want to sync, copy the text and paste into a new note. Then delete the old one. A little tedious, but works.
1) First you'll need to sync your iPhone/iPad with iTunes. Make sure you've checked the box to "Sync Notes" under "Other" on the "Info" panel of you device. Also, make sure to uncheck the box for "Replace information on this phone" in the "Advanced" pane and resolve any conflicts properly.
2) Once your notes are identical on your computer and your iPhone/iPad, open up Mail.app on your COMPUTER and scroll down your accounts tab on the left (panel may be hidden by default) until you find the "Reminders" section. You should have a "Notes" section that has several accounts. Mine had notes from a Gmail acct, "On My Mac", and "iCloud".
3) Merge all the notes from the "On My Mac" acct and any others you need by selecting them all and dragging them to the "iCloud" acct. Once you're sure they're there, check back on your device that all your notes are now populating in the "iCloud" acct. (this may take 30 secs or so.)
4) Optional: I then deleted the gmail notes folder and the "On My Mac" folder to make sure any new notes would be created in the iCloud acct. I don't know if this will work or not.
5) Fianally, I deleted all the notes from the other accounts on my iPhone. I had to do this one at a time, which sucked, but someone my find a faster way. All I know is it works.