The Cheep Spinner is 4" deep x 6" wide x 3 1/2" tall (from the base of the feet to the top of the knob). This is a stand-alone model, meant to be used in conjunction with a keyboard. It can also be mounted as-is into a control panel (details will be forthcoming on how to do this). It's available in a USB model for $59*. (* Price does not include shipping. CA residents must add 8% sales tax. ADB units are no longer available.)
Update 12/18/01 - So what is all this Control Freak-Compatible hooey? Quite simply, the cord comes out a different place in the back of the case now (near the bottom, instead of the top) and there's now a switch recessed into the top of the lid. What's it for? Well, I like to call it the "operational mode status actuating inverter". What it really is, is an "on/off" switch. Why? Well, if you drop one of these into a Control Freak along with a Hackball, you don't want to accdentally hit one control while using another. Like avoiding spikes in Tempest, fer instance. You're whipping down the tube, and you let go of the Spinner, only to brush up against the Hackball, and WHAM! You're spiked. Similar icky things can happen with trackball games if the Spinner is nudged. Lemme tell ya, Crystal Castles can get pretty ugly.
So... both the Spinner and Hackball now have an on/off switch. This is not like unplugging the control though. As far as the Mac (and MacMAME are concerned) nothing changes. This means you can turn these on or off at any time, and never lose control.
Now... what if you already own a Cheep Spinner, and want to use it in a Control Freak someday to save a little money? Well, if I ever actually get around to building the Control Freak, I'll offer a way to upgrade existing Cheep Spinners for, well... cheap.