http://filezilla-project.org/ free transfer across all platforms, storage for windows
http://fetchsoftworks.com/ application for mac, cost depends on amount of licenses
open-source application for mac
http://www.smartftp.com/ application for windows, costs depends on licenses
http://www.coreftp.com/ free application for windows
www.mediafire.com free online file hosting
www.yousendit.com online FTP offering higher security/fewer limits, price varies
www.webcargo.com online FTP offering higher security/fewer limits, price varies