In principle, we all recognize that nothing on the Internet is ever truly private. Messages sent from company e-mail accounts are in theory the company’s property. Downloaded data passes through so many servers that it is no doubt stored by countless parties other than the sender and receiver. So far, for most people, this has seemed more a hypothetical problem than an urgent and unavoidable one. But if that changes, it’ll mean a moment of Dodgeball truth for all of us, when we recognize that the Web 2.0 era belonged to younger, more trusting people.

In practical terms, where does this leave me? With the experiment over, I doubt that I’ll use Writely again. (Yes, it does most of what I want in a word processor – but so does Word, and I can use that when I’m sitting on an airplane. Same for Google Spreadsheets versus Excel.) Maybe I’ll check out YouTube when someone sends me an interesting link. I’ll look at Wikipedia pages when they come up high in a search and I have a way to double-check any crucial facts. As for MySpace – nah!

But other applications have come to seem like natural parts of my daily life. Google Calendar is worth the effort – for the appointments that my wife needs to know about. I find that I leave Google Earth running all day, to check aerial views of a foreign site I’ve just read about or a neighborhood where I’m meeting someone for lunch. The discount travel broker Kayak has gotten my attention; eBay has retained it, for all the obvious reasons. Flickr is a good way to share photo files with my family – and keep them from jamming up my computer. I’ll continue using Gmail as a backup site for important data files. As Ajax-enabled sites spread, they’ll make sites that still require you to hit “refresh” or a “submit” button seem hopelessly out of date. I still don’t like the label Web 2.0, I will continue to mock those who say “mash up,” and I will never use Dodgeball. But I’m glad for what this experiment has forced me to see.

James Fallows is a national correspondent for the Atlantic.