I just received Google Calendar spam. I'll take some screenshots when I get home.
Heres an excerpt though:
   "Jared Cherup, you are invited to
hello dear

Fri Mar 21 9am – 10am
(Timezone: Eastern Time)

Calendar: Jared Cherup

My name is Joe Williams, a business merchant in Dubai, Arab. I have been diagnosed with Cancer which was discovered very late, due to my laxity in careing for my health.

It has defiled all forms of medicine, Right now I have only about a few months to live, according to my Medical Doctor.

I have not particularly lived my life so well, as I never really cared for myself but the oil business. Though I am very rich, I was never generous, "

http://farm4.static.flickr.com/3194/2306346638_ce6d12ef96.jpg?v=0
[screenshot by Andrew Huff http://flickr.com/photos/deadhorse/2306346638/]

Didn’t you get the memo? Email spam is out, and the latest trend (for spammers) is to spam/scam people over Google Calender. :)

Just like text messaging spam, IM spam. I can't wait for iPod spam...

This is taken from Google groups messages – can be useful to everyone:
http://groups.google.com/group/google-calendar-help-misc/browse_thread/thread/18742b9ef209c472/e8ff376635545fc7

Start Quote
"
Google Calendar Guide Google employee
   Mar 18, 3:20 pm
From: Google Calendar Guide
Date: Tue, 18 Mar 2008 12:20:53 -0700 (PDT)
Local: Tues, Mar 18 2008 3:20 pm
Subject: Re: Fix Google Calendar SPAM
Reply | Forward | Print | Individual message | Report this message | Find messages by this author

Hi everyone,

I'm really sorry to hear that you're receiving reminders for spammy
events and seeing these events on your Google Calendar. The team hates
spam just as much as you guys do and we're working hard to keep it out
of Google Calendar.

If you've enabled notifications for "New invitations," you can
configure your Google Calendar settings to only show events you've
created or accepted:

1. Click on "Settings" at the top of any Google Calendar page
2. Select the "General" tab if it isn't selected already.
3. In the "Automatically add invitations to my calendar" section,
select "No, only show invitations to which I have responded."
4. Click on "Save."

In the future, you can also report any cases of spam by going to
http://www.google.com/support/calendar/bin/request.py?page=&contact_t...

Thanks for letting us know about this behavior.

- Becky
"
End Quote

I wonder how long it will take for google to add "mark as spam" buttons to all its apps, it would really discourage people to start spamming in for example google docs, in which it would be quite easy...

I was spammed too!

I thought the spammer was ingenious though, in a spammy spam way

I've received spam invitations from Google Calendar via email, and I don't even have a Google account. To add insult to injury, when I tried to report it via the webform I got the following email bounce back, as it included the entire content in the X-Trak-Extra-Content header:

Delivery to the following recipient failed permanently:

   gmail-form+maingoogle.com

Technical details of permanent failure:
PERM_FAILURE: SMTP Error (state 16): 552 5.6.0 Headers too large (16384 max)

thanks a lot for this. i feel like i've killed a monster before it spread and took over. i'm so posting this into my blog (hallalavida.blogspot.com).

James,

I just tried, and it is perfectly possible to send Google Calendar invitiations to any email address. Good for spreading Google Calendar use, no doubt, but also good for spammers.