I've developed a widget for people who fish to track their catches. I've implemented a lot of different features into this widget including: recording GPS locations of catches, weather data, database functionality, Google maps cluster mapping, a photo album, sharing catches by email, and a filtering system. Take a look if it interests you.
https://market.android.com/details?id=mindware.fishwidgetbeta
https://market.android.com/details?id=mindware.fishwidgetbeta