On: "No Dashes Or Spaces" Hall of Shame

[uggedal]

Paypal shows icons of all major credit card companies below the credit card number field. When you start typing the non-matching card types gets grayed out.

[jamesbritt → uggedal]

That is really quite clever.

It's the sort of idea one wants to generalize and steal for other things on a site.

Makes me wonder if there are any sites that showcase or catalog non-trivial/non-obvious UI techniques.