In celebration of π Day (3/14) 2007, Day Late & Dollar Short Software has released piClock shows the current time (and, optionally, the current date) as strings of digits within the decimal expansion of the ever-popular mathematical constant, π = 3.1415926535… . The widget displays the four digits before and after the string as well.
The Show Position of Digits in π option identifies the location of the date or time string in π by showing where it starts.
More info and download link (donationware) here.