I spent quite a bit of time trying to find the Easter eggs crammed into the Watchmen movie...heck, I try and do that for all the comic book movies I watched!
While I got some of the more obvious ones like references to The Black Freighter comic book that is an integral part of the graphic novel, the Village People appearing at the front of Studio 54, just behind Ozymandias, and the Comedian being responsible for Kennedy's assassination, there was quite a lot of stuff that I missed.
Here are two sites that highlight some of the Easter eggs from the Watchmen movie that you might have missed.
The first one is absolutely brilliant, with stills from the movie and picture comparisons!
Easter Eggs (And Missing Parts) In Watchmen's Titles
The second one is more of just a regular article, but it's still pretty good:
'Watchmen' Easter Eggs: Our Favorite Blink-And-You'll-Miss-'Em Moments