I'm trying to teach myself how to use Modern Persistence Patterns (OR/M, Repository, etc) and development practices (TDD, etc).
Because the best way (for me) to learn is by doing, I'd like to build some sort of demo application for myself. The problem is, I've got no idea what sort of application to build. I'd like to blog about my experience, so I'd like to build something of some worth to the community, but at the same time I want to avoid things that others are actively doing (web commerce, forums) or have been done to death (blog engines).
Does anybody have any suggestions for a good pet project I could work on and maybe blog about my experiences with?
There are innumerable community-service organizations with little or no web presence.
Pick a service organization -- any one -- Literacy Volunteers, Food Pantries, Home Furnishings Donations, Alcoholics Anonymous -- anything. The grass-roots community organizations benefit the most from involvement; they often need a more dynamic web presence but can't afford it.
Look at their current web site. Build them something better. Donate it to them.