CudaMiner builds are now available for Mac OS X 10.6 (Snow Leopard), Mac OS X 10.7 (Lion), and Mac OS X 10.8 (Mountain Lion) in addition to the already available builds for Mac OS X 10.9 (Mavericks).
For binaries and instructions: CudaMiner for OS X
For updated instructions on compiling CudaMiner yourself: Mining Litecoin on Mac OS X with CudaMiner
Please note that CudaMiner is only available in 32-bit for OS X 10.6 (Snow Leopard) due to the 32-bit only CUDA drivers. CudaMiner for OS X 10.7 and higher is available in 64-bit.