Small Helpers

7-Zip is a file archiver with a high compression ratio. Absolutely free and ready to use for anybody, I use it more that a few years. Also it has handy command line version - I use this feature in my .bat files for automatically archive my source files, I am very lazy to find good backup software:)

The main features of 7-Zip

• High compression ratio in new 7z format with LZMA compression
• Supported formats:
  • Packing / unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
  • Unpacking only: RAR, CAB, ISO, ARJ, LZH, CHM, Z, CPIO, RPM, DEB and NSIS
• For ZIP and GZIP formats, 7-Zip provides a compression ratio that is 2-10 % better than the ratio provided by PKZip and WinZip
• Self-extracting capability for 7z format
• Integration with Windows Shell
• Powerful File Manager
• Powerful command line version
• Plugin for FAR Manager
• Localizations for 63 languages

You can find a some bit of information about compression ratio at homepage.