In my free time, I try to keep up with web development for my personal sites. Over the last year, the gem of my side work became the 'Waterfalls of the Keweenaw Area' website, a truly complete and detailed project. Due to this project, I learned more about Google Map API, KML files, and general content management then I would have by waiting for appropriate job projects. The waterfalls site involved much more than just making a website - I had to go out and collect the data (photos, directions, GPS points) manually - and now I have several ideas for future projects stacked up.
One project that is mostly completed is a Daylight Tracker. This application will print out calendars and graphs with sunrise/sunset information based on the current latitude and longitude of a user. While it's completely functional, I've decided to overhaul the frontend to utilize jQuery and JSON as an additional hurdle.
The next project on the radar is a full page Google Maps application that I can start linking my photos, hiking trips, and waterfall information to. Some interactivity might be allowed, such as commenting on hikes/photo locations or adding new points of interest as an open source experiment. Also, depending on how easy the API works with KML files, I might allow exporting/importing of KML files, but definitely would avoid storing imported KML files on my server.
An idea that I've had for several months is a Flash-based Timeline application. Pulling dates in either a singular 'Point in History' or 'Timespan' format from a database, this application would allow a user to move forward/backward along the timeline as well as a zoom feature to see more detail or less important items. I'd want to be able to categorize the data too, so users could choose what points to see. Not only would this be a dandy way to expand on the About Me portion of a website, but I'd offer the raw files up for download for other people to play with and utilize on their own projects.
There's a few other projects lower on the radar, including a personal financial tracker and creating an API interface from the waterfall site data. However, I'm sure that these projects are plenty to keep me busy for the summer.