This was my first big web job back in 2000. Originally I was tasked with creating an event entry system to allow Victorian schools to enter their students into the Interschools Snow Sports. It was a massive success and has evolved into an extensive entry system that is used nation-wide, to take over 10,000 students entries. On top of entry management, the system is required to generate various starting lists, reports and data files for integration with the different resorts' race timing software. It also manages invoicing and BPAY ids.
The entry system runs off Coldfusion, as this was the best (IMHO) Server-side language at the time.
I am now responsible for management of all aspects of the site, which includes an ancient bespoke ASP classic CMS, which keeps me on my toes. One cool thing that I extended the CMS to do, is a newsletter builder that allows both custom content and inclusion of content from the site. Also have updated it to manage video, both flash embedded and HTML5 native.