I'll back it. In nine words or less: Huge blue penis. Swinging cerulean wang. Kobalt azure schlong. But also, the movie pointed out some stuff to me that was in the comic that I didn't catch, so for that alone I think it's worth it.
Watchmen the comic is a really big deal: although you read it like a book, many of the pages are in a triptych format. Therefore, each panel makes sense in itself, but when you take these panels together, you have another meaning. Since each image is frozen, you can do this with a page of comics or a painting--but how can you accomplish this with a movie?
Alan Moore, Dave Gibbons, and John Higgins use panels and images symbolically in a way that would be incredibly hard for a movie to do. Ex: there's a panel where the Comedian is being held by his lapels by someone off-panel, and his expression is somewhat... broken and resigned? Crushed? This image is mirrored a few times throughout the comic: once again when the Comedian is holding Moloch by Moloch's lapels, with a similar or the same expression but with more confusion on the Comedian's face; once when Moloch is being held by Rorschach, and Moloch just looks afraid; and then a final panel with Rorschach in it, looking angry while clenching his fists, holding no-one. This image is used, I think, as a symbol for how each character deals with horrible lethal reality that contradicts their constructed narrative--and so partly how each character grieves, and at what stage they are in their grief. How easily they can admit to being wrong, maybe. I don't know.
Issue V, "Fearful Symmetry" is more or less symmetrical, with the first and last panel of the issues matching in the way a Rorschach blot might; the middle of the issue is arranged in a triptych which roughly sketches an "X". This is not just pretty artwork: this is a graph of the story if you were to use a Structuralist reading. The Rhetorical term for this is Chiasmus: the beginning of the novel is more or less a 'who done it' story, with clear rules and morals for at least one of the characters. At the end, that rigid and certain character is rendered (in my mind) conflicted to the point of begging to be killed--since upholding his rigid and certain rules would likely lead to billions dead, and compromising would mean admitting how much pain and torture he's inflicted on others, and been subjected to himself.
Watchmen the comic does not need to be read linearly. You can bounce from panel to panel, based only off of connections of images, and have quite a lot of meaning in it. (ex: John's smile while looking for a subatomic particle when Laurie goes off to dinner with Dan is the same as his smile when he looks down at her right before walking over the pool in Karnack--since time's not linear to him, and since he almost never smiles, I think this means he purposefully looked for the particle when he did, and it was his blessing for the poolside scene.) Non-linear time is a theme in Watchmen; the sequence of events is almost secondary to the connections between them. For example, a traumatic event is seen reflected and distorted in Moloch's Solar Mirror weapon; when this traumatic event is brought up later, the hearer's reflection is seen distorted upon a snow globe; finally, when this event is dealt with and grieved over, the person is reflected either in a bottle of perfume or in a crystalline structure on Mars, I can't recall which one. Each interaction with that traumatic event is significant in itself, yet they're all connected. (Sometimes the close reading doesn't work, like when Rorschach's distorted reflection is seen in Ozymandias' gold supper dish... I don't think those are connected.)
Here's a site with a really good close reading of Watchmen, issue by issue:
http://iat.ubalt.edu/moulthrop/hypertexts/wm/watch.cfm But yes. I'm in favor of the movie, as it used much of what Moore, Gibbons, and Higgins used. So go see it.