Windows/Mac/Linux (Firefox): The Firefox Uploader extension provides a universal interface for uploading files to popular web applications like Flickr, Box.net ...

Dropbox today rolled out a new feature that will allow those without an account to share files with Dropbox users. Called “File Requests,” the option gives anyone you ask the ability to upload files ...

Windows does not have very many options for quick file uploading, and the ones that do exist aren't fantastic. The best of the pack is probably FluffyApp, which uploads to the previously mentioned ...