Features used:

• When the form is submitted, all user input is validated.
• In the screenshot 3 field values were not accepted. There is no need to push the back button. The incomplete fields are in red, and a description about each error is displayed on top of the form.
• All "must" fields are marked with a *
• The focus is automatically set to the first incorrect field. See the cursor in the field "Location".
• All fields have automatic access keys. Alt-f will bring the user to the "Firstname" field.
• The fields are grouped into "Person", "Contact" and "Intended Usage".
• No template is used here for the rendering. The look is default behavior.
• The Bs_Onomastics plugin is used to validate sex, firstname and lastname.
• The country select field is a built in field, no need to deal with the country list or any db access.
• The syntax of the email address is checked. The field is set to not allow freemail providers.
• The "URL" field is defined as datatype "url", and thus the syntax is checked aswell. It is no "must" field, that's why an empty value is accepted. But "asdf" would not be OK.
• The "Description" field has a minLength of 40 characters. But we don't want to annoy people, so the warning can be "overlooked" after a first incomplete submit. This way the user still thinks about what to fill in.
• Once all input is valid the submitted data is automatically persisted into a db table.
• An email is sent to the webmaster.
• The number of seconds used to fill in the form and the number of submits (until everything was accepted) are tracked.