Another easy way (assuming they both have Internet access) is to share a Dropbox. While the free account is limited to 2GB, I find it incredibly convenient to have all my PCs, Macs, and Linux machines (even smartphones) sharing a single Dropbox account, at least for smaller files. And it's smart enough to not use the Internet if the files are being transferred locally. Plus, you get automatic backups. And should you take the laptop on the road, you *still* have connectivity between the laptop and desktop.