Here is a list of all the free software that I would recommend:

Sugar Sync – File Syncing Program that also gets backed up securely in the Cloud:
File Syncing Program that will allow users to share files/folders that will sync automatically to your other computers and allow you to nagate the use of USB sticks and the risks of losing the USB stick.  The files/folders are also sync’d (Upto 5GB to start with) to the Cloud securely using 128 bit AES encryption.
The link below give you an extra 250MB (500MB before 31st May 2011) as you will become a referred user and every person you refer to use Sugar Sync you will also get another 250MB of storage space in the Cloud:
https://www.sugarsync.com/referral?rf=bg8idwpbd9e7x

7-Zip – File compression and extraction:
This is a free open source file compression/extraction software that supports a wide range of comporssion formats including rar files.
Here are the main features of 7-Zip:
High compression ratio in 7z format with LZMA and LZMA2 compression
Supported formats:
Packing / unpacking: 7z, XZ, BZIP2, GZIP, TAR, ZIP and WIM
Unpacking only: ARJ, CAB, CHM, CPIO, CramFS, DEB, DMG, FAT, HFS, ISO, LZH, LZMA, MBR, MSI, NSIS, NTFS, RAR, RPM, SquashFS, UDF, VHD, WIM, XAR and Z.
For ZIP and GZIP formats, 7-Zip provides a compression ratio that is 2-10 % better than the ratio provided by PKZip and WinZip
Strong AES-256 encryption in 7z and ZIP formats
Self-extracting capability for 7z format
Integration with Windows Shell
Powerful File Manager
Powerful command line version
Plugin for FAR Manager
http://www.7-zip.org/download.html