I travel frequently and used to do it by a portable hard drive. Portable hard drives go bad so fast, I was spending a hundred bucks every three years. This is amazing because you can use it offline as well. It's easy to use (in my opinion) and I think it has the best interface. I use 3 ...
Dropbox makes our retail life easier. We share all documents internally and selected documents externally. The storage is large so we upload tons of inventory images.
Free up to 2 GB
$9.99 / month up to 1TB
$12 per user per month - unlimited storage