I post photos from my G+ account all the time now. I click on the photo in G+ to bring up that black-backgrounded viewing mode, and then just right click on the photo and copy the image URL. Might be cumbersome if you have a LOT of photos to get links for, but it does work. Note my recent post about the AFL doctor with the massive moustache; that photo's hosted over on G+ and linked in to my LiveJournal.