I’ve been using flickr for about a year now.  I’ve never had a need to download a lot of photos at one time because I have a copy on my computer at home.  But, if something tragic happened to my drives, it’s nice to know there’s a relatively painless method of downloading them all at once.  Chris at DSLRBlog.com recently posted his downloading script.  I’d try it out, but I don’t have a need right now.  If you use it, let me know how it works.