This small solution that does not need server side code (I love it), is a combination of the JS API build by Darren and JQuery. JQuery is so easy to use and it is perfect to manipulate SharePoint.

To make sure that the XMl web parts work we have build in a small function that fades out the quick launch so that you can see that the JQuery call works. Below screenshot shows what you should see on your page after uploading the XML (no server side installation needed).

Preparation
You need to take care of the following preparations:

• Create a new blank site;
• Upload zsLibrary.stp to your list template gallery;
• Upload dropdown.dwp, jquery.dwp and startfill.dwp to your web part gallery;
• Create a new list based on the zsLibrary;
• Add the web parts dropdown.dwp, jquery.dwp and startfill.dwp to your page;
• You should be ready to rock and roll!

When you click on Fill list we will call a SP web service at the current site to get all lists. By using JQuery we fill the dropdown list without refreshing the screen, it is fast and slick.