Big PowerPoint files are becoming an increasingly big problem. Yousendit is a convenient service that allows you to send very large files. You upload a file to the server, the recipient receives an email with a link to download it. FTP without the hassle.
Today, yousendit launched a plugin for Microsoft Office. It's the same functionality that the web site offers, but now with a tighter integration into Excel, PowerPoint and Word.
Be aware of security issues though. If you use the standard transfer mode, anyone "guessing" the download URL can get to your file. Secure sending options are available but are not free of charge.