dropbox is a good utility for sharing files and images and music and anything pretty much, so is googles version...google files or some such
check out dropbox!
https://www.dropbox.com/
otherwise copyrighted things arent really a worry, so long as its not utilised for financial gain its pretty much fair game
...so you can share images to friends, but you cant use the image as a logo
https://dl.dropbox.com/u/37212962/675464...7141_z.jpg
thats how you share with drop box, nice n easy, just dragged and dropped the file in the folder, copied the public link and its all done, but im sure theres a way of making a group folder which we all have and can all use/make changes to :-)
i just checked and its really easy to make a collaborative folder in dropbox and let people use it!...took me all of 2 minutes to find out how
oh and sharing folders is only if you got a persons email adress, so theres no chance of letting unknown sheeple into the folder!