I’ve just found one of the best uses for MSN Messenger, just add encarta@conversagent.com to your MSN Contacts and ask it a question! It’s great, for example

APC- says:
what is the capital of australia?
Encarta® Instant Answers says:
The capital of Australia is Canberra.
APC- says:
how many people live in the UK?
Encarta® Instant Answers says:
There are 49,561,800 people (2002) people in the United Kingdom

Or the best, it solves maths too

APC- says:
Solve 2x^2+7x=5
Encarta® Instant Answers says:
Equation Solver:
Let’s solve the quadratic equation:
2x^2+7x = 5
First we need to put the equation in the form:
ax^2 + bx + c = 0
For this, we set the equation to equal 0, and arrange the terms from the highest exponent to the lowest:
2x^2+7x-5 = 0
We have:
a=2 b=7 c=-5
We can now apply the quadratic formula:
x = ( -b ± ?(b²-4ac) ) / 2a
We find two solutions:
x=0.60849528301415 or x=-4.1084952830142

How good is that!