The advantage it has over PHP and ASP is that its runs on the client machine and not on the server meaning that pages do not need to be reloaded when a script is run. The disadvantage is that it can be turned off in the users browser so you can't guarantee that a script will run.
Below is a screen shot of our 2 click time selector in action
Initially the hour values are displayed next to the text box where the time is entered. Clicking on one of the hour values puts the value in to the text box (and defaults to 00 minutes).
After the hour is clicked, the minute values are displayed. Clicking on one of these adds the minutes to the selected hour. The hours are then displayed again ready for input.
The hour and minute values displayed are fully configurable and it is much quicker than scrolling through drop down lists.
Even if you only want to add an image rollover effect to your web site, ask us for a quote and we'll do our best to give you a competitive price.