I think that one of the most underutilized CRM data types is the BIT field.  Most people are thinking bit = on/off, 1/0, etc., and they would be correct.  But what the most facinating thing about this data type is how you can display it.

Once you have created the Attribute and added it to the Form, double-click on the field to show its properties.  Click on the Formatting Tab.

Take a look at the Control Formatting section. This is where you can change the display properties of the BIT field, of which there are three:

Now this may not seem like a big deal, but it really does open up user interface design possibilities.

In addition, you don't have to stick to the standard Yes/No choices. Remember, this is a binary selection, which means you have two choices.

What if you replaced Yes and No with Married and Single?  That would give you fexibility of design while restricting the data entry to one of two choices.

It's really nothing more than a two-selection picklist, but with extra design options.