The times they are a-changin’.
This post seems to be older than 16 years—a long time on the internet. It might be outdated.
I finally got around to packaging up the Add User Photo plugin. You can download it here. Go to the plugin page, Add User Photo, to grab the latest copy. Unzip it and upload to your plugins directory, and then activate it. You also need to modify line 21 of /wp-admin/profile.php, adding enctype="multipart/form-data" to the form tag.
So at the end of the day, line 21 should look like:
<form name="profile" id="your-profile" action="profile-update.php" method="post" enctype="multipart/form-data">0