The folks at AddTo have just released a new iPhone and iPad app.
This app covers Portland Oregon and you can find it here.
The idea behind the AddTo apps is to give you specific information about a location, but let you write notes and take photos that you can build into an album. The app builds a map of all the places you visit and write about or take photos at. These locations are placed onto a map so you can see what you were thinking or seeing at specific spots.
You can export your notes, photos and even the map via email, which is invoked by pressing the lower right action button in the application.