As of Build 0.16, Gcal Mobile supports event deletion. While that may not seem particularly noteworthy, it means that you can now use Gcal Mobile to cancel meeings on the go. If you told Google Calendar to send invitations for an event when you created it, deleting the event in Gcal Mobile will send each attendee a nice note informing them that the meeting has been cancelled:
The note also includes an .ics file that will automatically remove the event from compatible calendar programs. Pretty neat, huh?