On The Serverside.com there is a JSF Custom Component article, and probably you came from there expecting the full explanation of my StockQuote example component. It is currently 15:00 (3pm) so I have to do some business before I have time for a full disclosure.
In the mean time, you may want to check out the CVS code:

Via viewcvs, you can see the files here. The component is called 'StockQuoteLabel', and is defined in the file StockQuoteLabel.java.
The web page files are StockQuote.html and StockQuote.java.