A selection of my in progress and finished work:
Respond, the wordpress theme you can see running on this blog.
This is a fully skinned wp-theme which required editing PHP and understanding the wordpress platform. Fortunately, there is a wealth of information to help developers who want to work with wordpress, not least the codex
An ajax-based chat app, styled with CSS3
A timesheet app built with MySQL & PHP
The idea behind this was to solve a problem encountered at work where our timesheets which were manually filled out by us and then entered into a spreadsheet were often copied wrongly and also done so at the time expense of our office admin. By automating this, we are able to save time and money.