There are chances all the time to use your sense of humor and to lighten and brighten up your day, and hopefully the days of others. For example, today I had to attend a meeting for all the staff where I work. Normally our amazing office manager takes the minutes/notes and then writes them up and sends them out for all to see. Well, today she couldn't do it because she had other responsibilities, so I did it. Needless to say I made the minutes short, sweet and funny. Of course, my supervisor had a few editorial changes, but he left in some of the best parts.
How to make it funny...use acronyms specific to your organization or comments that people in your organization or group would understand and appreciate (I wrote something about using post-it-notes to write our clinical notes and as it gives us the ability to destroy them by eating them if confidentiality could be compromised--certainly something that therapists/counselors at our office could relate to). Also instead of boring words like "discussed" use words like chat, or blah, blah, blah for discussions that gone on and on. Of course, timing and taste are everything when attempting to inject humor, and if you have doubts, let someone with a good sense of timing and taste read it over before you put it out to the masses.
Here is a bit of Visual Humor. It is a site where there are many interesting and some humorous signs--some intentional and some are just plain "what were you thinking?" Enjoy: http://seehere.blogspot.com/2006/08/strange-and-funny-signs.html