Will.i.am Hologram
It's like he's really there! CNN

When Turkish prime minister Recep Tayyip Erdogan couldn't attend a recent party conference he did the only thing he reasonably could – he sent a 10ft hologram of himself to speak instead.

Hang on, holograms aren't supposed to be real! They're one of those science fiction creations that are only ever supposed to be a few years away from becoming a reality – like the one-calorie cheeseburger or decent football commentators.

The Turkish PM's move got us thinking about the best and worst examples of celebrity holograms – and there are more than you might think.

Tupac Shakur

Bringing people back from the dead as holograms to perform is a concept a little hard to stomach, but that didn't stop Coachella organisers bringing the sadly departed hip-hop legend back for a performance alongside Dr Dre and Snoop Dogg in 2012.

This wasn't nearly as bad as bringing back Audrey Hepburn to peddle Galaxy chocolate or Steve McQueen to sell Ford cars. It was handled with as much decorum and respect as you could hope from something that isn't a world away from connecting someone's corpse to a series of ropes and pulleys.

Warning: Strong language

Will.i.am

In early November 2008 the US was on the verge of electing its first African-American president, and everyone knew it.

Predictably, news outlets attempted to load their schedules with prominent black celebrities, asking for their insight into the historic events that were unfolding. Many had genuine insight, some were Will.i.am.

Apparently unable to make it in to CNN's news headquarters, and no doubt wanting to avoid an embarrassing face-to-face interaction with respected TV journalist Anderson Cooper, Will.i.am elected instead to appear as a hologram.

Maybe someone, somewhere, thought a black president was such a far-out and futuristic concept that holograms seemed apt? I hope not... okay, maybe I do.

Lewis Hamilton

Charismatic dynamo and regular Formula One also-ran Lewis Hamilton is exactly the kind of man you want advertising your products – especially if they're banks or phone networks.

Or Reebok! Rather than being unable to attend and having to send in his hologram self with his hologram tail between his hologram legs, Lewis appeared in person at the event alongside his ethereal, digital self.

Holo-Hamilton introduced his fleshy self on to the stage before sharing some awkward tele-prompter banter with him and disappearing into the space Poochie-style.

Frank Sinatra

Right, time to come clean, this isn't a hologram so much as a screen with Sinatra on it, but it's an important benchmark in the admittedly small collection of dead musicians singing with living ones, for reasons we'll get to in a second.

Handled with some class, but with little of the shock factor that came with Tupac, Sinatra appeared at the 50th Grammy Awards in 2008 to sing Learning the Blues with Alicia Keyes. It was a nice pseudo-duet, but why is it here? You mean to say there's a similar example of mind-boggling awfulness?

Elvis Presley

If Elvis Presley ever returned from beyond the grave we'd hope he'd have better things to do than duet with Canadian inanimate object Celine Dion.

The year was 2009, and someone in charge of American Idol took a ton of drugs, then decided that this definitely needed to happen, and would be a good way to spend thousands of dollars.

Technically, it is impressive (if, as with Tupac, it actually worked in person as well as on screen) with both appearing to share the stage to sing If I Can Dream, so at least it has that going for it.