Anything that you use for your job can arguably be deducted as a misc. business expense. Example include those mentioned, second phone lines, new uniforms (above whatever your company pays), notebook computers you use for work, cellphones (on reserve?), professional organizations and periodicals (Aviation Week, for those who can still stomach it), etc.
You can always hire a tax guy and go through this with her/him as well ... and you'll get a better answer.