I suppose it depends on how you think your users will want to interact with your content.
For example, when paging through blog archives, I think a simple older/newer model works, especially when several blog entries are shown on one page (and a more comprehensive archive exists, such as posts by month/category/whatever).
With things like forums, I tend to agree with the "1 ... 7 8 9 ... 30" model. I don't think the number of pages in the "center" of the page numbers matters, so long as it's not too excessive. It could be lower if you don't expect that many pages to exist, or longer if you expect a huge amount of pages (i.e. google, as per the example in your question).
There are a number of other models that can work depending on what you're paginating (for example, "prev, next, go to page:") but like many things, it depends. There's no one universally correct answer.
But, it's not that big a deal after all. If you screw up your pagination model, I'm sure there won't be a significant amount of damage as long as it's somewhat usable.