Apple Store has the refurbished
Unibody Apple Mac Mini with Intel Core i5 and Thunderbolt MC815LL/A (Mid 2011) on sale for $469
with free shipping. Measures 1.4" x 7.7" x 7.7" but no longer has an optical drive. This configuration has a 2.3GHz Sandy Bridge Intel Core i5 CPU, 2GB memory, 500GB HDD, Intel HD 3000 graphics and eligibility for free upgrade to Mac OS X 10.8 Mountain Lion.