Google Calendar to compete with iCal

Expected for months, Google Calendar is now available.

It is an online calendar application which can be accessed and shared from any computer, something similar to other services such as Plaxo.
It can also send "reminder" or alarm message to mobile phones.
Google can directly compete with iCal since as stated in the Google Calendar FAQ:

Does Google Calendar connect to other calendar applications and devices?
Yes. Google Calendar uses open calendar standards to give you more choice when it comes to accessing your calendar. You can view your schedule using any application or device that accepts iCal or XML files.

For additional information:
calendar.google.com