Page titles are a key consideration by Google when looking at your website as to what exactly the page is all about. The key is to name your titles with the keywords you are looking to optimise the page for.
Laser eye surgery from Laser Sight Centres
Pages throughout this website change title as you move from different content areas. This is good SEO since you are customising each page to particular keywords and not just targetting your generic words.
This also comes back to the principle of 1 page for 1 keyword.
Any questions or comments please post.
N.B. This is a forum I read to get some new insights and opinions to our own search engine optimisation http://www.searchengineforums.com/