Thanks for the DeCAF plug! Here's a demo of the classifier with the pre-trained ImageNet weights in action: http://decaf.berkeleyvision.org/
I also have to take the opportunity to plug Caffe [1] - Yangqing's replacement for DeCAF which he actually open sourced just a few hours ago. All the heavy processing (e.g., forward/backprop) can be run either on your (CUDA-enabled) GPU or on the CPU, and the GPU implementation is actually a bit faster than cuda-convnet. The entire core is (imo) very well-engineered and written in clean lovely C++, but it also comes with Python and Matlab wrappers. I've personally been hacking around inside the core for about a month and it has really been a pleasure to work with.