Get ready to smile lots - and probably buy a new hard drive.
Every mission photo from Apollo is on this site, and I mean every. This even includes end of roll / damaged photos that don't appear in the official NASA numbering of the roll - I didn't even know these existed.
This is a little fiddly but follow the steps and you'll be able to download huge, high-quality Apollo photos. (Mac users - I found it impossible to get this site to work on Safari for some reason. I've used Netscape without problems).
Go to: The Gateway to Astronaut Photography of Earth
Hover your mouse over 'Find Photos' in the menu near the top of the page. From the drop down menu that appears choose 'Search', then 'Mission-Roll-Frame'
From the menu of missions scroll down and select your Apollo mission of choice (I'll use Apollo 9). If you have a particular photo number in mind fill in the 'Roll' and 'Frame 1' boxes. If you want to browse thumbnails leave this blank. Scroll down to 'Choose which kind of records to display (optional)' button. Click it, then select 'All digital images including those that have not yet been cataloged'. Now scroll down and hit 'Run Query'.
On the results page tick the 'Show thumbnails if they are available' box. Now browse the 28 pages of Apollo 9 photos until you find one you like. Click on the frame number of the photo, NOT the thumbnail.
On the next page scroll down to 'Large Images to Request for Downloading' and hit 'request'. On the next page follow the instructions to download the file either through your web browser or ftp software. It states a delay of up to five minutes, but I requested about 15 files in one batch and they all came through in less than a minute.
If you're interested in seeing an example the file I requested is an uncommon photo of Schweickart's EVA. Check out the reflection in Schweickart's visor of Scott standing in the CM hatch.
(I presume this file is only temporary so don't be surprised if this link has expired.)