Sambuka

I just installed the google tool baar, and heard everyone saying PR1-2-3 is good, WHY? Does it show how often the domain is indexed by the search engines or what?

I'm a search engine newbie, never really paid any attention but I have some great plans for SE's if I can work out how they work.

Anybody tell me why thehun has PR6 and my site has PR3. does PR mean much all or is it nothing?

Sammy