Besides doing logical expression, Leopard Spotlight can also do some mathematical calculations. Are you curious what are those functions?
I know a little bit about Java Programming Language, so I try to use the Math library, which contains some functions to do scientific calculations, on Spotlight. To my surprise, some of these functions work.
Here are some examples :
Trigonometry

sin(0.5) = 0.479
sinus of 0.5, result in radian. 
cos(0.5) = 0.878
cosinus of 0.5, result in radian. 
tan(0.25) = 0.255
tangent of 0.25, result in radian. 
asin(1) = 1.57
arc sinus of 1 radian. 
acos(1) = 0
arc cosinus of 1 radian. 
atan(1) = 0.785
arc tangent of 1 radian.
Approximation

ceil(0.48) = 1
Rounded to nearest smaller integer value. 
rint(0.51) = 1
Rounded to nearest integer value.
Exponential and Logarithm

exp(2) = 7.389
Euler’s number e to the power of 2. 
pow(5,2) = 25
5 to the power of 2. 
sqrt(36) = 6
Squareroot of 36. 
cbrt(216) = 6
Cuberoot of 216. 
log(1e3) = 3
Logarithmic base 10 of 1*10^3.