Is there anyone that says that the "us" in "let us make man btzelem elokim" is referring to humans I'm working on a d'var Torah at the moment and hoping for a source to back the idea up that Hashem was telling us to continue working on it.
There's a well-known comment (I don't recall who off-hand) that it's G-d's invitation to the person reading the text.
On a related note, Rabbi Ovadiah Sforno (Italy, died c. 1550) has the fascinating concept that each person decides for him/herself just how G-dly they will be; thus, how much do they fulfill the original engineering specification of "in G-d's likeness." (This appears in Sforno's essay prefacing his commentary on the Torah.)
Found it - apparently the Yismach Moshe says this. At least according to http://www.youngisrael.org/content/parsha/01%20Beraishis/Berayshees08MichaelBorenstein.cfm and other divrei torah have come across online