Microsoft is providing Windows Server 2008 R2 180 day evaluation for the general public.
You can Register to download Windows Server 2008 R2 for 180 evaluation using following options.
Register to download Windows Server 2008 R2 Windows 2008 R2 Standard, Enterprise, Datacenter, and Web which is available in the following languages: Chinese (Simplified), English, French, German, Japanese, and Spanish.
Register to download Windows Server 2008 R2 for Itanium-Based systems
Available in the following languages: English, German, French, Japanese
Remember that Windows Server 2008 R2 is available in 64-bit (x64) only. Check out the Windows 2008 R2 System Requirements at http://www.microsoft.com/windowsserver2008/en/us/system-requirements.aspx
You may also want to see this website: Convert your Windows Server 2008 R2 to a Workstation!.
PS: Windows 2008 R2 Logo - Copyright Microsoft