There are some actors who seemingly come out of nowhere and take over every Hollywood blockbuster going, or, indeed, transform lesser films into potential cash cows. Orlando Bloom did such with his appearance as Legolas in the Lord of the Rings trilogy, going on to gradually shuffle his way to the front of ever-diminshing returns in Pirates of the Carribean and bolstering the ad campaigns of lame duck side-projects such as The Calcium Kid. Whilst in recent times Sam Worthington has suddenly appeared as the star of Titanic director James Cameron's mega-budgeted 3D epic Avatar, as well as head-lining Terminator: Salvation and the up-coming remake of Clash of the Titans. His Titan's co-star Gemma Arterton has had a similar ascenson, bursting onto the scene in Lad's Mag friendly reimagining of St. Trinian's, going on to pop up in Quantum of Solace and - like Bloom - bolster the ad-campaign of lame-duck side-project Three and Out; not to mention the fact that alongside Clash of the Titans she'll be in the next potential franchise starter from Pirates producer Jerry Bruckheimer: Prince of Persia: The Sands of Time. Phew!

But then there are some actors who seem to forever skirt on the edge of stardom, usually they seem much more deserving of the fame that so eagerly awaits them, but, thankfully, their forays into the mainstream are fleeting at best. It is of my opinion that Johnny Depp is one of the more recent actors to take the plunge from 'interesting character actor' into Hollywood poster-boy and I feel it's a sad loss for his career, but not too late to turn things around (fingers crossed).

With the arrival in recent weeks of two highly different projects things may be about to turn around for Joseph Gordon Levitt, and I nervously watch his up-coming slate. Levitt made a name for himself as Tommy on family-friendly aliens on Earth sitcom Third Rock From The Sun, which managed to run for five inexplicable years and rake in a wealth of awards; though Levitt was no stranger to film and television having been acting since the age of seven. As a teenager he took on roles in the obligatory slasher movie (the not-as-bad-as-any-of-the-other-sequels Halloween H:20) and one the best - and last- nineties' teen-movies, 10 Things I Hate About You (alongside Heath Ledger who had a similar balance to his career as Levitt).

Finally after providing a voice for the soggy Disney animation Treasure Planet (one of the ones you probably forgot they made!), his career took a surprising and intriguing turn. It began with his performance as Neil in the difficult, provactive and powerful Mysterious Skin, his portrayl of a teenage hustler growing up in a stifling small town should have at least earned him an Oscar nod (shockingly Johnny Depp was nominated for Pirates of the Carribean that year). After this came the cult phenomenom Brick, a remarkable teenage twist on the noir genre, that invented its own deliciously retro language and had a twisty-turny plot made refreshing and plausible by a gaggle of excellent performances, most notably Levitt's lead turn as a teen trying to uncover the truth behind his ex-girlfriend's disappearance.

Usually it's these kind of underground roles that would push Levitt's name to the top of Hollywood casting director's lists; much like how Ledger's work in 10 Things... and Aussie crime-flick Two Hands won him roles in The Patriot and A Knight's Tale. But instead, since then Levitt's work has remained consistently low-key and off-beat.

But mainstream attention beckons with the summer blockbuster based on action figures; G.I. Joe: Rise of the Cobra, in which Levitt is practically unrecognisable, obscured by a big latex mask in the villainous role of The Doctor, and last weekend's American sleeper hit, rom-com (500) Days of Summer co-starring Zooey Deschanel (who also juggles the art-house with the popcorn). Coming projects on Levitt's slate include smaller films Elektra Luxx and Hesher, alongside the next film from The Dark Knight director Christopher Nolan; $200,000,000 sci-fi Inception; where Levitt we be sharing screen-time with Leonardo DiCaprio, Michael Caine and Juno's Ellen Page.

It seems strange to feel protective over the ascendancy of an actor that I think is one of the best and brightest working in Hollywood (or outside of it) today, but of late I've been dismayed by the forays - and eventual stays - when former screen favourites have been tempted to take on the blockbusters (yes, Johnny Depp, I'm still looking at you). One hopes that Levitt continues to flirt, teasingly, with Hollywood in order to keep funding these smaller projects and that when casting is under way for a new sidekick to tag along with Captain Jack Levitt makes the right choice and sticks to shore.