i just got a notebook and won a promo code by the interactive distractions podcast (props to them) and i got fallout. to download it, it gives me two options.
to download it using the browser or to add to downloader.
what is the best option to use?
i try to be very careful with what i do with my laptop and wonder what the add to downloader does? does it download by a gog program for the laptop?

The Downloader is a light weight AIR application for GoG downloads. The only function it has is to download items in its queue (100% safe).
That said, its personal preference - you can download via the browser just as easy as using the GoG downloader (the downloader is really good if you are queuing multiple downloads though).
Add to Downloader adds the game to the downloader queue (which it will check when started or refreshed).

The difference is pretty much convenience and reliability. The browser download is the same as downloading anything else from the net including the potential lack of reliability. If you have decent speed internet then you'd probably be fine with the browser download. The Downloader is a program that acts like a download manager and lets you pause & resume the download and also for the big games that come in multiple files, it downloads them all with a single command (I'm doing that right now with my new copy of advent rising). The downloader is slightly fiddly to set up (you have to install 2 things rather than just one, its double the work!) but worth it for the sake of reliability and long term convenience
Hehe and its got a long memory, I installed the downloader on my reformatted PC after months of not having used it and the server had actually kept the last thing I'd added to the queue

Directly through the browser is the primary downloading method, but the downloader is nice if you want to be able to pause and resume the download for some reason (if you have a slow connection and don't want to have the computer running for several days straight, if you have a download cap and only want to download at off-peak hours, or if you have an unstable connection that breaks every now and then...).