I read about this a while back so here is my understanding:
It does not store the web (physically impossible) for you, so the line
Search anything, anytime, anywhere is a little misleading. It actually stores a limited amount of data that's been scrunched up to smaller sizes.
So that's out of the way...what it does is allow you to do is store 'packs' of various sizes of different topics. So you can have it tailored to your needs. Basically your favorite Web sites, guides, Wikipedia, etc.
It stores the first page or two of a google search (not all 15,000 pages that you get from a live google search). So if you routinely get to page 3 or 4 of the google search before you find what you are looking for, then it may not be for you.
I have seen reports up to 80G being required.
It may have a use for people don't have web access (
)
But seeing as I have to connect to the web for my email, news, chats etc., I don't foresee me using it.