Grow HFS+ partition on Mac OS X without Disk Utility

I have Boot Camp set up, and I had shrunk my main Macintosh HD partition to make room for an Ubuntu partition. Turns out I didn't really want it as much as I thought I did, so I used a GPartEd live CD to remove the partition. However, it wouldn't let me grow it back. Turns out GPartEd can't do that. I called AppleCare to ask what I should do, and I was actually on the telephone for a little over an hour. They told me to use Disk Utility to grow the partition. I tried, however, and it gave me the error message "Partition Failed with the error: Filesystem resize support required, such as HFS+ with Journaling enabled." They tried to help, but they weren't able to solve the problem. I came across this forum post, however, and it mentioned the diskutil command, more specifically the resizeVolume subcommand. I tried this, and it worked! Here's what to do if you ever have the same problem:

1. Open Disk Utility.
2. Select the volume you want to grow, and click Info in the toolbar.
3. Note the Disk Identifier (from here on referred to as ????), and optionally quit Disk Utility.
4. Open the Terminal.
5. Type the following command: diskutil resizeVolume /dev/???? limits
6. Note the Maximum Size (not the part in parentheses.)
7. Type the following command: sudo diskutil resizeVolume /dev/???? [maximum size]
8. Enter your password if prompted.

In Step 7, do include the GB after the size, but don't put the space in between.

Here's a screen transcript of what I did in the Terminal in case it helps (highlighted lines represent what I typed): http://pastebin.com/hKMkCsQy