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My advice would be not to do this. I find it bad enough being forced to use a calendar control just to enter a date, especially when not given the option to type a date which I can do way quicker than navigating yet another wacky control.
Time pickers just take this kind of UI fetish to a new extreme. Why not allow your users to either type the time or just use a couple of drop down boxes for hours and mins. Even drop down lists allow a user to just type the time. The time picker in Shog9's answer is all very nice to look at but is incredibly fiddly to use. If I was an end user having to use a data entry app and it had a control like that on the page then it's only going to slow me down and make me want to come and cut off the developers hands. :)
Think about usability first before how slick the app looks.
Just my humble opinion.