Ever wondered what Google bombing was? Try searching for 'miserable failure' in Google and you'll see the most famous example of Google bombing. For a more detailed discussion take a look at http://www.moving-target-software.com/blog

Google's algorithm is based on the idea that when lots of different sites around the Internet all link to a particular webpage, that webpage must be darn important. And if popular, high quality sites link to the page, it must be really, really important. Another factor of this is if lots and lots of sites all link to www.daniweb.com (for example) using "computer forum" as the hyperlink text, it's a good bet that DaniWeb has a computer forum on it (even if the term "computer forum" can't actually be found anywhere on DaniWeb!)

Dani I think if you though about putting computer forum in some H1, title, h2 tags and so on you'll probably start ranking in Yahoo and the soon to be outdated MSN.

I'm one step ahead of you. Notice the thread titles, forum titles, and forum descriptions near the top of the page as you browse the forum? Those are all CSS'd H1 and H2 tags.