If you are swapping files on anything like a regular basis, why not install dropbox. If you both install it and share a folder with each other, then you just plonk the file in a folder on your machine and it will appear in the folder on his. I appreciate that there is the need to install it.
Otherwise 7-zip as mentioned elsewhere in the thread is great.
Edited by philippercival (Mon 03-Oct-11 09:43:17)