You know how much I love Google Calendar, and my obsession with Gmail? Well I can admit when something has a flaw and there is a big one with Google Calendar. Gmail lets you consolidate pretty much as many email accounts as you want and it works seamlessly, why can't Google Calendar get on the bandwagon. Most of the time when someone sends me a calendar invite they will send it to my lessdoing.com email address because that is the one I communicate with. Unfortunately if you click on accept you'll get a screen that basically says this is not your gmail account so you can't accept invitations to your gmail calendar. So I always find myself writing back to the person and asking them to send the invite to my gmail address. Now I've automated it.
Basically the filter is this:
invitation: ics -re: -fw: -accepted -meetup -canceled -declined
Which finds any email with a calendar invite and excludes cancelled, declined, accepted or mailing list events. Then it responds with an autoresponder canned response kindly informing the sender to resend it to my Gmail address.
The big benefit of this method is that the person should get such an immediate response that they won't even have had a chance to close their calendar app before they receive my request, reducing the inconvenience to them to a minimum and completely eliminating it for me.