I just saw this over on TrekMovie.com (click it to get the full list) and copied some of my favorites here … talk about fun trivia!  Who would have believed R2-D2 was in Star Trek?!?

• R2 is in the debris field. During the Drill Machine sequence as the Enterprise comes out of its barrel role amidst destruction of the other Federation ships above Vulcan, we cut to an interior Enterprise bridge over the shoulder of Kirk that is looking out through the front viewscreen. In space, R2-D2 is floating in the debris from about the top middle of the screen to the bottom right.
• The surround screen tests for the young Vulcan children are similiar to the multi-screen tests for the resurrected Spock in Star Trek IV
• Sign seen as Kirk drives motorcycle into Riverside Ship Yard reads ‘Sector 47′, the number 47 is a recurring theme on the Abrams shows Alias, Fringe and Lost, as well as TNG era Trek
• Another 47 mention when Uhura talks about “47 ships” from a Klingon armada that were destroyed
• During Kobayashi Maru simulator Kirk eats an apple, an homage to the Genesis cave scene in Star Trek II when Kirk at apple while telling story about how he beat the Kobayashi Maru
• Last name called for assignment was “Vader USS Hood”, reference to Star Wars
• When Chekov is trying to log in to his station the computer voice is by Majel Barrett Roddenberry, her last role in the Star Trek franchise before her death
• Sulu tells Kirk his combat training is in fencing, in the TOS episode “The Naked Time” Sulu shows off his fencing abilities
• Chief engineer Olsen wearing red jumpsuit dies a ‘red shirt’ death
• Nero tortures Pike using ‘Centaurian Slugs’ which are an homage to the Ceti Eels of Star Trek II
• Spock’s line “If you eliminate the impossible, whatever remains, however improbable, must be the truth” is the same line Spock speaks in Star Trek VI
• Spock Prime tells Kirk he “has been and always shall be his friend”, just as he said to Kirk in Wrath of Khan
• McCoy asks spock if he is “out of his Vulcan mind?”, a question that McCoy Prime asked Spock on a couple of ocasions in TOS and the movies
• Spock’s comment about “roaming the halls weeping” could be reference to Spock’s loss of control in TOS “The Naked Time”
• A tribble can be seen (and heard) in cage in Scotty’s workshop (on table he has his feet up on when first seen)
• Spock keying in the equation from the future for trans-warp beaming into Scotty’s computer is homage to Scotty keying in formula from the future for transparent aluminum into Plexicorp computer in Star Trek IV
• When Pike is seen at the end he is wearing admiral uniform very similar to those of The Motion Picture and is in wheel chair, as he was in “The Menagerie”