Have been playing with Ajax recently, and I have did some research on it as well(during holidays).
Well, I have tried using Sajax to create a dynamic table for data editing. By using Sajax toolkit, it can be done in less than 15mins(depend on your needs).
Visit Sajax website for more information and download the source code for example.
If you have created something interesting, please leave a message here or ping back. Thank!