Signing up was simple and easy and the amount of free storage is incredible. But storage to infinity isn't any good if you can't upload photos. I haven't been able to upload a single photo. I've tried groups, singles, saving to my computer, their old uploader, their new uploader. A google search shows this to be a very common problem after their site revamp. Flickr sounds awesome but I can't even use it.
In summary, I would not recommend Flickr to a friend.