Sharefest is a site that allows users to send files of arbitrary size via a P2P connection. To use it, go to the site, select a file to share, then give the link to friend. All they have to do is visit the URL and they'll be able to download the file you shared.
This transfer is directly from your computer to theirs, without the file being uploaded anywhere between. This also makes it easy to stop sharing the file. Just close the browser window and the file becomes inaccessable.
Sharefest is open-source! Check out the code on GitHub.