Skoot lets you invite people to "workspaces" where you can trade large files without the hassle of email attachments or FTP. You don't have to deal with your email client at all, just drop files in a special folder using your Finder. If your recipients don't have Skoot, Skoot will send an email to help them get started.
LicenseFree to try
Operating System Mac OS X 10.4 Intel Mac OS X 10.5 PPC Mac OS X 10.5 Intel Mac OS X 10.4 PPC Mac OS X 10.6 Intel Macintosh