For ridiculously small hard drives (8GB), what Ubuntu Based (although not necessarily official) distribution offers the smallest installed size?

Let me clarify:
I still want a certain amount of personal file space, preferably a few gig.
I also don't have a problem with performance, while it is mediocre, a 2.6GHz single-core and 1GB of ram suffice to run ubuntu fine, but i find that it uses 6-7GB of space. I am aiming for closer to 4GB.