The last time you applied for a tech job (or evaluated a résumé of someone applying for one), how much weight did you apply to expressing your skill with basic productivity tools like Microsoft Office or OpenOffice? My guess would be very little. In the résumés I've seen from prospective applicants, it's sometimes not even mentioned. After all, being conversant with tools that are such basic parts of life in business today might seem to be a given.
It's anything but. I've met and worked with highly skilled network, server, and storage engineers who have only a passing knowledge of Excel and Visio (or their respective OpenOffice equivalents). Although it may seem a little silly at first, I believe these skills are almost as critical as having a solid understanding of the infrastructure tech you're tasked with maintaining.
I spend an enormous amount of time working with Excel and Visio. Rather than just creating documentation for a job that's already been done, I routinely use them in the planning process, communicating design changes to business stakeholders and, in some cases, as a means for configuring hardware and services. I can honestly and unabashedly say that without Excel and Visio, I'd be almost unable to do my job.