I LOVE Dropbox! It is a free file sharing service that lets you upload files to your Dropbox account which you can easily invite someone to by giving them a specific link. There is the option to purchase more space, but so far I have not needed even though I use Dropbox quite a bit with graphic design as well as photography clients.
The site and everything about it is so user friendly! I have not seen another site as excellent and clear as this one. Dropbox also puts my mind at ease because I know whatever files I have placed on there are safe (in case my computer crashes or my office goes up in flames). If I have the need for recovering files, I can just download my saved files from Dropbox.com to another computer. (Dropbox also has an app for your phone but I personally don’t use it.)
It is free, easy to understand and they don’t send you a bunch of emails – a winner in my book! (No, they are not paying me to say this!) Take a look: Dropbox.com