> you can’t simply right-click the image area to save it

True, but taking a screenshot is not needed. Using Firefox, right-click then select "View Page Info", find the image on the "Media" tab and click "Save As".

> As your Knol pages too can use a Creative Commons license,
> you’re even allowed to use licenses which demand “share alike”

I don't think that's permitted. "Share-alike" means that anyone who uses the licensed work must also share their mashups under the same terms.

But Knol only allows two creative commons licenses: "Attribution" and "Attribution-Noncommercial".

So if I take someone's "Share-alike" Flickr photo and put it on a Knol page, I am breaking their license whichever way I license it in Knol.

If I make my page "All rights reserved", then I'm not sharing alike. If I make my page "Creative Commons Attribution" (whether unrestricted or noncommercial) I'm saying to others "you can use this material provided you credit the source, and you don't even need to share-alike".

What if I select "all rights reserved" and include the less restrictive license (share-alike) in the document?

In all fairness, there isn't some police force who goes around pulling down cartoons with the wrong licences ;-)

Ionut: that's a very clever solution, and seems entirely valid to me.

Incidentally, the XKCD cartoons are CC AT-NC and are therefore available for Knols.
http://xkcd.com/

It turns out there's no need to get a screenshot or save the New Yorker cartoons yourself.

When you're editing a Knol you can click the "Add an Image" button. One of the options is "New Yorker Cartoons" and you just need to paste the ID number of the cartoon you want (obtained from The New Yorker Store).

> > you can’t simply right-click the image area to save it
>
> True, but taking a screenshot is not needed.

Yeah, this (and potential other methods) was what I meant by "There are other ways to grab the image, but you can’t simply right-click the image area to save it." Someone may prefer this or that way. Thanks for explaining this method.

> > As your Knol pages too can use a Creative Commons license,
> > you’re even allowed to use licenses which demand “share alike”
>
> I don't think that's permitted. "Share-alike" means that
> anyone who uses the licensed work must also share
> their mashups under the same terms.

The CC ShareAlike license says (with my emphasis):
"If you alter, transform, or build upon this work, you may distribute the resulting work only under the same, similar *or a compatible* license."
Whether or not CC non-ShareAlike-required licenses are indeed compatible is a good question, I will ask Creative Commons support (or does anyone here know the answer?).

> It turns out there's no need to get a screenshot or save
> the New Yorker cartoons yourself.

Ah, great tip, I totally missed this method. They include a big watermark kind of copyright notice, so even then cropping may be needed, but the quality is very good for this method. I'll update the post.

> What if I select "all rights reserved" and include the
> less restrictive license (share-alike) in the document?

Wonder if that's OK per Google's terms, and also valid in terms of CC (i.e. to have two licenses in the document with unclear guidelines which is the "right" one... added to that there's also the "©2008 Google" in the footer).

In regards to which licenses are compatible with the ShareAlike CC license, the CC organization points to this table:

http://wiki.creativecommons.org/FAQ#I_used_part_of_a_Creative_Commons-licensed_work.2C_which_Creative_Commons_license_can_I_relicense_my_work_under.3F

If I understand the table right then the left row is the source license, and then you can check the top side for the target license. If that's right then it means you can only republish a CC-sa license using the exact same sa license.

I've updated the post again.