New to .NET 2.0, the System.IO.Compression namespace is very cool.

Using the GZipStream it only took these few lines of code to take a file and compress it to a neighbouring file with an extra .gz extension.

using System;
using System.IO;
using System.IO.Compression;

...

public void CompressFile(string filename)
{    
    using (FileStream fs = new FileStream(filename + ".gz", FileMode.Create, FileAccess.Write, FileShare.None))
    using (GZipStream compressor = new GZipStream(fs, CompressionMode.Compress, true)
    {
        byte[] buffer = File.ReadAllBytes(filename);
        compressor.Write(buffer, 0, buffer.Length);
    }
}

How easy is that? Nice.