Started to type in the search item 'five exclamation marks', with the helpful little drop-down thing offering suggestions as I went. When I had got as far as 'five e', the top offering was '= 13.5914091'. Which is indeed 5e, to the first seven decimal places.

And 'five times seven' gets you '= thirty-five'. (See my previous status.) Also does fractions, powers, roots and trigonometrical functions. Doesn't do factorials. Hmm—knows what phi is, even if you call it the golden ratio. Oddly, doesn't understand 'point'.

Actually does do factorials - 3 factorial (not "factorial of 3") gets you 6.

Oo! Oo! And log! 'log two' gets you the decimal log of two, while 'natural log two' gives you the natural log. Doesn't do antilogs. Or arc sine/cosine/tan.

Marcus Turner: Try asking it the the answer to life and everything..

Marcus - got as far as "life the u" (without the quotes) and it offered "life the universe and everything 42". It knows.

Marcus Turner: Try "7 miles in kilometres"

Just entered 7 miles, and it gave me 11.265408 kilometers [sic]. Doesn't do the reverse though, for either spelling of kilometres.

Hang on! 11 kilometres in miles gets me 6.83508311 miles. If I drop the final s from kilometres, the answer drops it from miles.

One piece of mathematical calculation you can do in the address bar that you can't do on any calculator I've ever seen is raise numbers to the power of imaginary or complex numbers. (-1) to the power of i = .0432139183, which is e^-π. π is pi. Stupid font.

Even does factorials of imaginary and complex numbers, but multiples of i have to be bracketed first. 3i factorial gives you 3× the factorial of i, not the factorial of 3i.

Here's a bizarre thing.
If a and b are both real numbers, then a^2b = (a^b)² = a²^b.
But if a = -1, and b = i:
(-1)^2i = 0.00186744273
((-1)^i)² = 0.0432139183² = 0.00186744273 BUT
(-1)²^i = 1^i = 1.

Just a folk mathematician—not the real thing.