I have a really, really bad memory: each time I need to install a Rails plugin, I Google to find the repository, then try to download the code. Often, I remember the url, but the server is down. Damn!

All this annoying issues kill the Rails rapidity on application prototyping. But, what if all the plugins which I need are available offline on my notebook? I can forget about all that urls, and I should stop to worry about the server status.