tweet with R

Pals,

I cannot load the twitteR package for R. After reading this brilliant entry on "R bloggers", I crave to do something alike, but fail to set the machine up.

I have downloaded the package and tried to call it, but R doesn't give me the green light. It says:

> library(twitteR)
Loading required package: RCurl
Error: package 'RCurl' could not be loaded
Además: Mensajes de aviso perdidos
In library(pkg, character.only = TRUE, logical.return = TRUE, lib.loc = lib.loc) :
there is no package called 'RCurl'

and when I look up this RCurl (which I have no idea what does) and try to load it manually, R says:

ERROR: dependencies ‘bitops’ are not available for package ‘RCurl’
* removing ‘/Users/lyolya/RCurl’

What shall I do with that, poor stupid me???