Here are a few web apps and sites I've made, which you may find useful.
- FindForMe.net - An automated shopping assistant.
- Debian Auto-package of the day - A fully automated introduction to exciting new Debian software packages. How did you ever get by without this!
- WhatHeaders.com - An HTTP client inspection tool that reports the request headers. Useful for understanding "black box" web clients like mobile web browsers.
- Daily Tao Te Ching - A mobile webapp version of my native iPhone Tao Te Ching app. The iPhone app has a much nicer interface; the mobile webapp has the advantage of working on other smartphones. There's also a twitter Tao Te Ching if you're into that - updated from a Python bot on one of my web servers.