I read about a nifty service over on TechCrunch today. It's called YouSendIt, and it allows you to email files of up to 1 GB to people without it actually taking up their inboxes (plus it provides a way to avoid that annoying size limit on attachments that many email services employ). Recipients get a link in their email that allows them to download the file. You can only send one file at a time, but it sounds like this service could potentially be pretty useful.
Then again, I can't think of any really large files to send that would cause me to need to use this service, but I'm sure there is something out there.