KeyGhost PS/2 keyloggers are VERY reliable but to a paranoid mind that has the slightest bit of computer knowledge, they are easy to spot. Having a large cylindrical device hanging off the back of your PC isn't very stealthy.

I have tried to "inline" USB converters using KeyGhost but it did not work. I used the USB to PS/2 adapters that come with the Microsoft intellimouse.

KeyGhost SX, however, is MUCH smaller and harder to spot initially.

MsMitts,

From the keyghost website FAQ.....

Q. Does the KeyGhost work on a USB keyboard?
A. The KeyGhost does not currently work on USB (rectangular plug) keyboards. There are no adapters available to make it work on a USB keyboard. KeyGhost only works with PS/2 keyboards (small round plug), and older DIN style keyboards (larger round plug, but requires adapters).

http://www.keyghost.com/faq.htm#usb