Whether it's for the office team-building offsite event or the weekly sales status summary, a quick way to add impact to your emails is with the Insert tab in Outlook 2007 and Outlook 2010.
You can add shapes, such as arrows, flowcharts, and word balloons:
And search through clip art for the perfect image from right inside your email message:
Here's a fun example that I created in less than a minute using a shape and clip art picture from Office.com:
All I did was this: Insert the callout shape, type and bold the text inside the balloon, search and select a clip art image, and then give it a quick 180-degree flip using a right click, Format Picture, and 3-D Rotation.
The good news is that the recipient doesn't even need to be using Outlook; most modern email clients display images. So take a moment to consider the presentation of your mails and be creative.