I too have been thinking about using them. I found a similar item here for a 2 or 3 dollars less:
If theft was a concern, then you could simply put a wire loop through it and the wheel itself, and lock it that way. If someone REALLY wanted it, they could cut that wire, but it would discourage the passerby......
Computers manufactured by companies such as IBM, Compaq and millions of others are by far the most popular with about 70 million machines in use worldwide. Macintosh fans note that cockroaches are far more numerous than humans and that numbers alone do not denote a higher life form. -NY Times 11/91