Okay, first of, feel free to suggest this might be a ufo, but first i wanna look at what normal thing it could be.. so this is what i saw:

it was about quarter to nine in the morning, i know this because i was walking to work at the time, the sky was completely grey but it was relitvely warm. In the sky i saw a black circle, it was completely black and completly still. it was about a cm across in perspective, but obviously much bigger down to the distance. It stayed there for my intire walk to work, i watched it all the way and was gone by the time i got out of work.


What ever it was, it had to be lower than the clouds, as the sky was completly covered in clouds, any suggestions?

Where do you live?
About four years ago I too saw a large, black dot or sphere here in Utah.
I was just west of Highway 36, on Highway 99, near the burg of Rush Valley. So, I was about 50 miles southwest of Salt Lake City. These are not major highways, in a rural setting.
I was admiring the great, puffy clouds over the Onaqui Mountains, southwest of me, when I saw a coal-black sphere flit between two large clouds. There was not much distance between these clouds, so the sighting lasted a second, perhaps less.
This was not a conventional aircraft because it was close enough to see clearly. It had no wings, tail or gondola below (as in a balloon).
I live near US Army Dugway Proving Ground and am familiar with the types of aircraft typically seen, such as F16s, C17s, C130s, etc.
This was simply a large, very black sphere.
Doubters have said it was just something in my eye. Yet, it was too well-defined for that. Dust, optical cells, etc. are typically fuzzy around the edges and have no sharp definition.
I've had my eyes checked faithfully each year by an ophthalmologist and there is no evidence of glaucoma, cataracts, etc.
So, I'd have to say that what you saw is believable in my experience, perhaps less believable in the experience of others.
I'd be interested to know whereabouts you saw this object.

Now that really makes it more interesting, my sighting was a black sphere exactly as you described it, coal black no wings, perfectly spherical. Here comes the interesting part, i live in england in a rural village, that happens to have an MOD proving ground (thats english ministry of defence) . How bloody Strange....

You see, the town i live in is Called "MOD________" (the blank is the name of the town, feel uncomfortable saying the real name). The town is completly flat accept for one huge hill, covered in trees and surrounded in barb-wire, Armed guard in unfiform at the gates. No-one in my town truely knows whats in there, but the hole town is full of american and english military bases.

The fact that both of our sighting were the same, and in similar locations is quite the coincedence..