I\'m interested in an online application like the tool that comes with XCode, that shows the keys and values as rows, in an editable manner and handles xml plists (I don\'t care
So, I was wondering the exact same thing, and when I saw this question and its answer, I said "Screw it, I'm making one!" And so I did. Two days later, here's my answer to you:
http://tustin2121.github.io/jsPlistor/
jsPListor (version 1 as of Aug 8th, 2013) will allow you to paste in the contents of an xml plist into it (via the Import button) and edit it with drag and drop and the like. When you're done, hit Export and it will package it all up into a valid plist for you to copy and paste back into the file.
There's still some bugs and glaring vacancies (like the Data Editing Dialog), but it functions. Future versions will attempt to allow saving via html5 download, and loading of files into data rows.
Feel free to examine, contribute, and submit bugs at the github repo: https://github.com/tustin2121/jsPlistor