I was up until recently using yousendit.com for transfering large files. I got an excellent free trial on their business users account - it allowed me to send 2gb files, track the downloads and clients just had to click the link I sent them to download. Now that the trial has expired I can do none of the above, there are malicious looking ads on the client download page and people have to register to get the file! The business package was great but its not worth $25 a month.
So does anybody know of a similar free site that can be used for transferring large files?