I’ve been using Google Calendar since it was released last month, and I have to say that its completely awesome. I had been using the 30 Boxes beta for a couple of months, but it just can’t compete with gCal. 30 Boxes had promise, but I predict it’ll vanish quickly now because of Google.
Why do I like Google Calendar so much? It’s got the ability to quickly add appointments (Dinner with Casey 6pm tomorrow) like 30 Boxes does, but it really shines in its sharing features. Sharing your calendar and subscribing to other ones is extremely easy, as is sending invitations to others. The Gmail integration is great too, letting you create a new calendar event and associate it with an email message.
The only thing I’m still wishing for is some way to automatically add items from my Microsoft Outlook/Exchange calendar. Many others are looking for the same thing though, and with the release of the Google Calendar API, it’s only a matter of time before someone figures out a solution.