Wow this is awesome. Some of the things are so subtle sometimes that I don't notice them.

That's good. It is subtle but any die hard Firefly fan would notice.

I did get it, but it was Quick...

Ah. Kinda (very) hard to catch if you don't know what you're looking for...

I don't get it...

So...what the heck does it mean, anyway?

dude...that IS obscure.

There was also a browncoat hanging behind the door (about 10s before this shot)

I really need to take the time to watch Firefly. Starbuck keeps telling me to.

Has anyone confirmed if the B&W print in Castle's Condo is a "firefly"?

Also, there was an X Files reference. "Trust No One" Thanks Rob Bowman

LOL I was thinking that was it. thanks for confirming!

I missed it the first time but that is totally it! AWESOME!

Na Castle's really just trying to do Mork's handshake nanooo nanooo ;)

Yet another chance for me to LoL at an inside joke whilst my friends look on in utter confusion... thanks Castle! :)

ha! nice! I also like how Agent Casey has worn a 'Blue Sun' tshirt in Chuck too!

It was hard to catch the specific (rather than really vague) reference but captured the pic leaves no doubt.