When I am not on my main workstation and need to upload or download graphics and other things, I tend to use web-based ftp to access my webservers. The only web-based version that I have found to be quite good and free is the java one called
UnlimitedFTP. You will need to register an account to use the service but each account works with multiple ftp addresses and you can share folder or partial ftp rights if you need that. The site also offers pay services but I have not used any of those since the free one is all that I need when I am mobile.
Here is the website for those interested:
http://www.unlimitedftp.ca
Always a friend to stray pixels,
KyleOdin