Curse you, GMail calendaring

Today I had two people send meeting invites (Content-Type: text/calendar) to one of my GMail accounts. Ordinarily, I can read ICS files just fine: OS/X knows what to do with them: bring up iCal and add them to my calendar. Unfortunately, GMail has decided to do me a favor: instead of just letting me download the attachment and fire up the appropriate helper app, it fires up its own calendar app and offers to let me add the event to my Google calendar. My what? I don't even recall asking for a Google calendar. Apparently, I can subscribe to that calendar in iCal via CalDAV, but that's not what I want: I just want to add the event to my ordinary calendar.

OK, this is irritating but workable. I'll just forward the message to one of my other mail accounts which I read with IMAP/Emacs and then download the .ics file and open it with iCal as per usual. But nooo.... When I forward the message, Gmail strips off the .ics attachment and just sends a text version. How, uh, helpful.

Oh, did I mention that the iPhone doesn't seem to be able to handle .ics either? I read these same messages via IMAP on my iPhone but the attachment just sits there. Outstanding!