Of all the series from this past season, it's 'Entourage' on HBO which will probably do the most towards expanding the TV Universe. Most of its contribution is coming from all of the celebrities appearing as themselves who can then link to other shows in which they appeared as themselves (but not as other characters).
My crossover comrade, Thom Holbrooke, the "Grand Poobala" of the Crossover/Spinoffs page (http://www.poobala.com/crossoverlist.html), seems to dismiss these cameos as casting stunts and not as legitimate links to other TV shows. But as for my more expansive vision of the TV Universe, these celebs are fictional versions of themselves, what I call "tele-versions". And they're welcome under the big tent of Toobworld.
Stars like Milton Berle ('Here's Lucy', 'CHiPs'), George Burns ('Alice', 'Wendy And Me'), and Sammy Davis, Jr. ('I Dream Of Jeannie', 'All In The Family') are so much larger than life, it's hard to look past that and see them as any other fictional characters.
Jack Benny was such an indelible impression with his fictional version - with the violin, the car, the vault, his age, and his overall stinginess - that I wouldn't be surprised if there are still people out there who believe that really was him. (Of course, I wouldn't be surprised if there are even more people nowadays who don't even know who he was. As somebody once stated, we are a nation of amnesiacs......)
At any rate, 'Entourage' averages about two celebrity cameos per episode, featuring boldfaced-type names from Jessica Alba to Mark Wahlberg (one of the creative forces behind the show). And each of them has the potential to connect the dots to some other show. There are also fictional references to other celebrities who don't appear (like when Ari Gold the agent mentions sharing sake with Sophia Coppola in Tokyo while she was filming 'Lost In Translation'.)
Two of the biggest links came from Jimmy Kimmel and Gary Busey. Since the concept of Toobworld covers all kinds of shows, then variety programs, talk shows, and reality shows are just as viable as the dramas and sitcoms. Now normally, I tend to ignore talk shows and sketch comedies as qualifiers if the celeb in question is just a guest. But when that celeb is the actual host or star, that's a talking horse of a different color.
So with Jimmy Kimmel, 'Entourage' makes the connection to 'The Man Show' and with 'The Jimmy Kimmel Show'.
As for Gary Busey, you can't get better validation than a reality series with your name in the title ('I'm With Busey')!
I've already removed 'Entourage' from my list of crossovers I'd like to see because apparently HBO was hip to the same possibility. In an interview with Entertainment Weekly, Jeremy Piven (who plays Ari Gold) said:
"Larry David plays himself as one of my clients, and that was one of the best days of my life. Going toe-to-toe with that freak was fantastic."
Some fudging and obfuscating (fancy fudging) may be needed if Larry David or Ari refers to 'Curb Your Enthusiasm' as an actual TV show. But I've packed away that same kind of fudge (sorry about that) when it came to appearances by Jerry Seinfeld in the post-'Seinfeld' era. (Unfortunately, with his three former co-stars, I was not able to remain the master of my domain. I'm still stuck for a splainin as to how they could refer to 'Seinfeld' as a fictional series on 'The Larry Sanders Show' when both series should be in the same universe.)
But as for that 'Entourage'/'Curb Your Enthusiasm' crossover, I hope Larry David's cameo can be kept within the bounds. HBO must know it'll be good publicity and good business. Hell, it has to be a no-brainer if I thought of it!
There's another strong possibility for a cross-over using celebrities; in fact, the names of these particular actors have already been invoked on the show:
Each of them appeared on a recurring basis on 'Movie Stars'. They were the poker buddies of Todd Hardin, who was an actor struggling in the shadows of his more famous brother and sister-in-law, Reese Hardin and Jacey Watts.
The same situation occurs in 'Entourage' with Johnny Drama tagging along after Vince Chase, his younger half-brother and a star on the rise.
'Entourage' is also good for universal expansion with the fictional movies and TV shows it's come up with:
'Head On' starring Vince Chase and Jessica Alba
'Queens Boulevard' - Vince's next project
'Mattahorn' - a 'Die Hard in Disneyland' that Vince turned down but now to be made with Colin Farrell
'Viking Quest' - a show cancelled seven years before but finding new fans via reruns on the Sci-Fi channel (Johnny Drama was one of its stars)
'Entourage' has already been renewed for a second season, so we're sure to find even more links to other TV shows thanks to all of those cameo appearances as time goes on.........