Here is a quick tip that you can use in your v7 Kentico sites.
Version 7 ships with a new option to apply watermarks to basically all the textboxes that run through the forms engine. The watermark allows you to show a text in the textbox when it is empty, for example to prompt the user for the expected input. You will also find the new watermark setting in some web parts like the smart search box (which we use a lot). Simply specify the watermark text and view the result.