I think it's Extras-Devel. For all that are using N900 for the first time: First you should go to this link with your mobile's web browser: http://repository.maemo.org/ Then you should click install on the fremantle extras-devel. After that click yes to activate it in App manager. Let App Manager refresh itself on demand. then go to X-Terminal and type: Code: root apt-get update apt-get install preenv If you still have problems, then post it here, I am sure maemo users will gladly help you.
root apt-get update apt-get install preenv