I was composing a reply to a thread this evening about the Clarity slider on a forum at Photoshop User.
I decided to go ahead and work up a Photoshop CS3/CS4 action set that provides an effect similar to the Clarity slider in Lightroom and ACR. It's free to anyone to download and use. http://www.thelightsright.com/TLRClarityEnhancement
The action gives "pop" and "snap" to photos. In the past, I used USM with a high radius and low amount, based on the recommendation of Michael Reichmann and Thomas Knoll. This new action set follows Mac Holberts' recommendation and uses High Pass with a large radius setting.
The action creates a Smart Filter layer, sets opacity to 25%, rolls off the deep shadows and the extreme highlights with Blend If settings, and applies High Pass filter. The Blend for the Smart Filters layer is set to Luminosity to reduce color shifts.
Be sure to let me know how you like it. I can easily adjust the settings based on feedback.
Happy Thanksgiving to everyone!