I always ask permission to use another's photo, I tell them the purpose, and once permission is granted, I send them the link to my blog. On my Tombstone Tuesday post of December 22, 2009, see Tuesday Tombstone - James Bishop, you really couldn't read what was written. The monument was so old, but since I had a map with his plot marked, I knew it was his, plus I could read a little of the inscription.
After I copied my photo into my genealogy software, and published that blog, I then went to Find-A-Grave. Once at the site, I checked to see if there was already a pictureof the Bishop monument and if not, I would submit mine. Talk about luck. I now saw the same cemetery monument with an engraved plaque at the base! I was pretty thrilled. Rob graciously let me copy his photo. See FindAGrave site with the James Bishop tombstone to view that page.
Moral, not a bad idea to often check your ancestors graves at FindAGrave sites to see if additional photos have been posted. And, always read the messages left. I have found distant cousins that way.