Have you ever had to:
a. take a screen shot of just part of your screen
b. try to match your web page color to something on your screen
c. figure out how wide to make a div or table cell

Working as a program manager at Microsoft typically means you take a lot of screen shots.  Screen shots of web pages, screen shots of application prototypes and (yes) screen shots of screen shots.  There are a ton of tools out there that do a number of these functions, some free, some not.  My current favorite tool happens to also have my current favorite price.

Mezer Tools from Bayden Systems is a free little app with a very appropriate icon: a Swiss Army knife.  This great, multi-purpose tool has widgets for measuring linear pixel dimensions and capturing arbitrary rectangles.  The dialog box also has additional tools for converting to and from Hex and for grabbing colors from anywhere on the screen.

 
Screenshots (made with Mezer, of course), click for a closer look.

Here's a list of some of the cool stuff you can do:

• Double-click the edge of a window to grow to the edge of the screen (not maximize)
• Capture a target window or just an arbitrary section of screen
• Capture screen to clipboard or directly to .JPG or .BMP
• Flag screen captures with arrows or scribbles
• Copy arbitrary string lengths to clipboard
• Measure the number of characters in the clipboard
• Grab the hex and RGB values from any location on the screen
• Convert from hex to decimal and back