Not directly related to testing, but this is a must have development tool - Multiplicity. I've been using it for a week now, and I think I'll buy a license today.

Multiplicity allows you to control multiple machines using one mouse/keyboard. I have a dual monitor system at home to begin with, but I keep many client files on my laptop because that's what I take on site. With multiplicity, I have three screens on my desktop, access to all my files (without having to set up a share or network anything), and for all practical purposes, I don't know it's a separate machine.

You can also copy text back and forth using the clipboard -- it's not much, but I've already found it handy for code and text from documents and emails.

Check it out. Also noteworthy, it's been up and running for a week now and I haven't noticed any bugs. Something rare...