The characters surnames are all representing a King and his household:
Gary KING
Andy KNIGHTLY
Stephen PRINCE
Oliver CHAMBERLAIN
Peter PAGE
A building can be seen with three banners (I believe its a construction site, if I recall) hanging on the exterior wall. They read "We build. We Innovate. We Improve". Tying in to the network robots.
The Pubs, as Edgar has stated in interviews, are like tarot cards that give you hints as to what's going to happen in each:
The First Post- One of the most obvious, they start here.
The Old Familiar- The pub looks exactly the same as the First Post. Also, Oliver's sister Sam arrives, stirring old familiar feelings in both Gary and Stephen
The Famous Cock- Gary is the famous Cock; or rather the infamous one. He is banned from the pub for his behaviour on previous nights.
The Crosshands- Our heroes first have to fight the robots. Crossing hands, as one crosses swords. The pub sign features five hands gripping eachother. One hand for each of our heroes. The hands have spatters of blue on them
The Good Companions- All five guys act like especially good friends, trying to not arouse suspicion. Gary is the only one having a genuinely good time. The Pub sign features 5 drama masks; 4 morose faces and one happy fool.
The Two Headed Dog- Here, they fight the twins. The sign has spatters of blue on it.
The Trusty Servant- Talking to Reverend Green, they discover the truth here about how humans are expected to behave. Reverend Green is the network's trusty servant. Although its not revealed until later, this is also where Oliver is replaced with a replicant. He too is a trusty servant now. The man on the pub sign looks a lot like Michael Smiley, who plays Reverend Green.
The Mermaid- The boys are seduced here by the siren song of the MArmalade sandwich: 2 blondes with a redhead in between. The pub sign features three mermaids; two blondes with a redhead in the middle.
The Beehive- The hive mind mentality of the network is revealed. One could also say Andy stirs some serious shit up here, kicking the bee's nest so to speak. The sign has spatters of blue on it.
The King's Head- Gary King is the only one to have a drink here. The King on the sign bears a pretty good resemblance to Simon Pegg in a wig. Also, the "Ooh, Ah, Dracula" Fruit machine from Shaun of the Dead can be heard here.
The Hole in the Wall- An obvious one, Stephen drives the Beast through the wall, creating a hole through which they can escape. Gary escapes through the window (Another hole in a wall) The sign has spatters of blue on it.
The World's End- The crew trigger the apocalypse.
Every pub where they fight the blue filled robots, the sign has spatters of blue. This one I didn't actually notice while watching, I noticed afterwards when I wanted to corroborate my theories on the meanings of the pub names, and found a link with images of the signs.