We use SEO (search engine optimization) here at PRO all the time with our topic titles. For example if a member starts a thread with a title "Urgent help need please!!!" we change the title to read something like "Help needed with XP Vista Dual Boot". The idea is to get key words into the topic title and the body of the post so that it's more likely to be what someone will search for at google or yahoo.
The threads with the most views are those that are really well optimized. Check out this post
by Mark (imnuts) for an excellent example of that. It has the most views of any thread ever here at PRO.
Another type of optimization is that for specific browsers, so a site could be optimized for IE7 or for Firefox or both. There are sites that give you an idea of how a site appears in different browsers.
I'm no webmaster but I think Jason and Mark can give you more ideas about this.
"The great majority of mankind are satisfied with appearances, as though they were realities, and are often more influenced by the things that seem than by those that are." - Niccolo Machiavelli