writes "I wrote a review of the Unicomp Customizer Keyboard, which is a modern version of the IBM and then Lexmark Model M much beloved by nerds and hackers. The pros of the Customizer: it's sturdy, remarkably similar to the Model M, has great tech support, and uses a USB interface. Oh, and it's Mac-friendly. The cons: at $69 it's somewhat expensive, and its noise won't be music to your cubemate's ears."
Note: this is one of the very, very few buckling-spring keyboards you can get new these days, instead of prowling through thrift stores, eBay, and university dumpsters.