And buy a years worth of 'Personal Plan'..
This includes 'Unlimited Sub-Domains' which i am led to belive is like http://jack.google.com?
(Say that google gave out sub domains)
would that be correct?
and, then once i've given out my subdomains to friends, or high level users,
if they were to upload a file to their http://jack.skullpop.com, would its space use come under My space? like, would www.skullpop.com lose 5megs?
It depends on the provider. But normally if you have a website hosting account which includes sub-domains the diskspace the sub-domains use will be taken from the total space you have allocated for your website hosting account.
An example of a sub-domain would be 'subdomain.yourdomain.com'.
You should ask the host you are reviewing, because "subdomains" are defined differently from host to host. Also, whether or not you can manage allocations per subdomain will depend on how the host arranges its plans, perhaps what type of Control Panel they use, etc.