[eluser]Dam1an[/eluser]
I havn't run any benchmarks on this approach, but if you plan on using this many times in a single helper function, then I would recomend just assigning the CI super object to a variable, as the overhead of making multiple calls would probably impact performance, although I'd imagine it would only make a nticable difference if you did it many, many times.
@Lima: Although the function itself would work in PHP4, the example of doing CI()->something() wouldn't, as method chaining only works in PHP5+