I am the co-worker Travis is referring to! Apple should buy Flickr (for the cross platform subscriber base and I agree it would be cool as part of a cross platform .Mac) for the reasons Travis mentions, but they won't because iPhoto is not cross platform and they already have iTunes which is crossplatform, does photos and has a recurring revenue stream and online store.
A co-worker of mine said I should blog about why Apple should buy Flickr -- and whether Flickr should sell to Apple, if anyone. I'd mentioned the idea to him because of all the rumor buzz going around and he said it was worth fleshing out. Fine, I said. And here it is: