I’m addicted to Web 2.0 apps—those interactive Ajax-scripted Web sites such as Backpack and Remember the Milk. The release of a new one reminds me of the pre-Web days when a new version of Mac OS or Quark would suddenly appear and you got to waste your whole day fiddling with new features. 30 Boxes is my latest obsession—a supersmart online calendar that could finally be the free solution to shared scheduling we’ve been waiting for. The beta just went public Sunday and so far I’m very impressed.

Besides its slick, easy-to-use interface, 30 Boxes’ schtick is that it integrates into the social Web scene, importing photos from your Flickr account, sites from your feed and content from several other sites. But it also lets you share your calendar with others in a very customizable way. Invite a “buddy” to join 30 Boxes, and decide what you want them to see—all or some of your appointments (you can set up individual filters), your bookmarks or Flickr photos, etc—and see theirs on your calendar. So you could share all your appointments with your spouse, only the weekly poker game with one set of buddies, and birthdays with all the relatives. Whenever you add something it shows up automatically on their calendars and vice versa. You can even drop Google maps into an appointment just by entering its address in brackets. Like any shared app, it requires everyone to participate to take full advantage of its potential, but even if none of your family and friends are on the Web 2.0 train yet, it’s worth using just for your own schedule. —Mike Haney