Why would you do this? Besides whimsy, analog clocks are actually pretty useful for instant information at-a-glance. Just a peek, and you immediately know roughly what time it is.
Analog Clock is available with several skins that resemble the look and feel of the standard XP visual styles. Skins are tunable, and you can switch on or off some of the interface elements (such as the second hand).
The app is an NTP-enabled application, and will update your system clock time by synchronizing it with atomic clocks through the Internet. It also includes a skinnable quick calendar window, accessible by mousing over the Analog Clock.