I haven't explicitly mentioned it in this thread, however if you follow the first link at the top of the discussion, you'll see that you can use the startat parameter to load into synths on specific images now.
The easiest way to get a link to a specific image in a synth is to:
1) scroll to it
2) pull up the 'Info' pane
3) click the chain icon (currently 4th after Facebook, Twitter, and Tumblr) to get a Share link to that image
4) copy that link and paste it.
Something that only works on synths that your currently signed in account has authored is to attach #warnings to the end of the view link, which will do the same thing as if you had clicked the 'omitted' link in a synth where some photos were unable to be synthed.
Note that the only person that this link will have any effect for is andyrblank (or someone who is using a computer which is signed into his account).