squeaky suspension/wheel?

I seem to be getting a squeak or creak noise from the front of the bike
whenever I decelerate or brake on my GPX250. It's kind of odd because it
modulates as if it were related to the spin of the wheel, but the noise
doesn't occur anywhere near as rapidly as the the wheel is turning. At a
guess I'd say 2 or three times a second, only when weight is pushed onto the
front.
Any ideas what this could be? I intend to take it in for a service, but I've
been a bit lazy lately.

 

Uncle Bully is of the opinion:

At a totally wild guess, you might have problem with your front forks.
Braking would put more pressure on them, and there's probably enough
variance that there'd be a bit of movement, and hence squeak.

Try squeezing the front brake and pushing the front of the bike down hard,
bouncing it. Any noise? If so, problem solved.

- Matt