If there is any character from the world of comics that gets a short shrift, it's Robin. Seen as the sidekick from hell, the DC Comics equivalent of Jar Jar Binks, he's been vilified for decades and been subjected to barefaced insults, accusations of deviancy, and even (successful) calls for his death. But still he endures under the tutelage of Batman, with people still scoffing at the idea of the character appearing in any media. Even Christian Bale said he wouldn't play the character if he appeared and Christopher Nolan confirmed that Robin would not work in his world.
Robin first appeared in Detective Comics #38 in April of 1940. Dreamt up as a way of attracting younger readers to Batman, he was also conceived as being the Watson to Batman's Sherlock Holmes, and subsequently made the comics even bigger sellers before getting his own book and a role as leader of the Teen Titans. There have been a few robins, but the notable ones are the original one, Dick Grayson (who would eventually become Nightwing), Jason Todd (who was murdered by the Joker in A Death In The Family), Tim Drake and Bruce Wayne's own son, Damien. Because he is the original and because he probably has the most compelling history, we'll stick with Dick for the long run.
Arguably the most famous example of Robin in the media comes from Burt Ward and the 1960s television show. Armed with hundreds of exclaimations beginning with the word "holy", and an uncanny knack for saying "Gee Batman!" a lot, he was easily excitable and full of spunk (probably Adam West's). So when someone mentions Robin, a million voices suddenly cry out in terror because they immediately assume that anyone playing the character will be full of krazy catchphrases and wear an outfit like Peter Pan. This is of course as ludicrous as imagining that any further adaptation of A Christmas Carol must have Bob Cratchett portrayed by a comedic frog. Of course, Chris O'Donnell in 1995's Batman Forever didn't exactly help things, generally acting like so much of a prick that it's no massive surprise that Bruce Wayne didn't want anything do with him, not that any character came out of that movie well.
However there is a precedent for characters being reinvented in the Batverse, even to make everyone forget the older version. The most famous example of this is probably Batman: The Animated Series, whose transformation of Mr. Freeze from a second-tier villain to one of Batman's most memorable antagonists not only changed the wide interpretation of the character, but also had influence far and wide, including Arnold Schwarzeneggar's "performance." However, the appearance of Mr. Freeze in the episode "Heart of Ice" by Paul Dini showed us a villain full of depth and humanity, one whose cruel actions are spurred on not by simple greed but by emotion and tragedy, in the guise of his terminally ill wife Nora.
Not that greed isn't a powerful - and realistic - cause. In fact, greed and the criminal actions that rise of its ashes were at the heart of another great character interpretation from the animated series, this time of Robin himself. The two-part episode "Robin's Reckoning" tells of a case where Batman shuts Dick out, much to the sidekick's anger. Peppered with flashbacks from the tragedy of the death of Dick's parents, it turns out that Batman is on the trailer of the murderer himself, and doesn't want him to be involved in case of emotional inbalance. The pair have a confrontation in the end, where Dick wants to kill the murderer, but his sense wins out in the end.
This is an example of how well the character fits. Bruce has a sense of responsibility for Dick, with the boy not having the support or resources that Bruce had at the time of his tragedy and the ensuing journey to becoming a beacon of justice. Robin serves Bruce with a reminder of of his humanity, and assists Alfred in making sure he never crosses that boundary into becoming what he fights. He also provides something Bruce can never attain as Batman: fatherhood, as well as someone to pass his mantle to. This also brings up a conflict for Bruce; should he be seeking someone to take over from him, to take the burden of Batman, or should he be protecting people like Dick from having to do this?
It's this kind of moral quandary that great drama can be based on, especially arising from the mirror image of Batman and Robin. Bruce looks at Dick and can only see himself, a ball of rage needing to be molded into something stronger and tempered. Dick looks at Bruce and sees a father figure who is too strict and excludes him without explaining a little too often, but also sees what he can eventually become if he applies the discipline Bruce has.
Of course, there is a certain youthful exuberance that Robin possesses that can provide a lighter side to the darkness of Batman. At times his role is pure wish-fulfillment, being the lucky kid that gets to fight alongside the dark knight and all that comes with that, including the cool outfits, the gadgets, and the pure adrenaline. The interplay between them, with Batman being the strong, silent and slightly grumpy type and Robin being the foil to that, is great at showing a sense of humour to them amidst the darkness that fans crave, as Dick takes the role of smartass kid to as much of a limit as Bruce will allow.
So how do you put Robin in a film? Or more pointedly, how do you fit a character like Robin into a world like Christopher Nolan's Gotham City?
There are a couple of ways to do this. Firstly, you can do the traditional Dick Grayson and mirror his tragedy with Bruce's. You can have him being a rookie cop, or a teenage tearaway, maybe even part of the homeless community we saw in the first film. You could introduce him like Jason Todd met Batman, who was caught trying to steal the tyres from the Batmobile. Obviously it wouldn't be realistic to try that with the Tumbler, but you could still have him trying to break into the vehicle. He could even try and mug Bruce Wayne, giving you someone so far away from Batman but driven to desperation for whatever reason that Bruce could see him almost as a project. As someone to help as his father wanted to, giving something back.
Robin would also be a good character to reinvent visually. With the lack of attachment many fans have to him, he could be ripe for a redesign and I'm sure Lucius Fox could knock something up for him. He could even have a cowl of sorts, maybe shaped like a bird, giving him a similar yet distinct look to Batman. Cues could be taken from Nightwing, indeed his outfit could even be black. He could have a kickass motorcycle, something similar to the Batpod.
The other way is to make Robin a girl. This has happened a couple of times in the comics, notably in The Dark Knight Returns. Given the high quotient of male roles in these films, the addition of a female Robin could try and even up the stakes a bit. The street-smart cocky dialogue Robin is famous for might also sound more palatable to some coming from a girl, and it'd give Batman a fresh challenge to work with. There are a ton of good young actresses to try this with - one of them (Juno Temple) is even in The Dark Knight Rises. Just don't mention Chloe Moretz, I don't think it'd work after Kick-Ass.
As a character, Robin really should get more respect. Whoever keeps making Batman movies, I hope he (or she) will get a place in there somewhere so detractors can see how interesting and compelling the character can be. Maybe even a certain Mr. Nolan will open his eyes to the prospect of seeing Dick Grayson on the silver screen, where he deserves to be.
Just don't let Akiva Goldsman anywhere near him.