Title tags seem to be a source of great confusion. Here's the low down in nice simple language.
What's a Title TAG?
The TITLE tag's (or element to use it's correct name) job is to identify the contents of a web page. It's useful because web pages are often referenced out of context, for example a search engine results page. It's a good idea to make the TITLE tag context-rich. For example, "Introduction" doesn't really work but "Introduction to kite surfing" does.
Should They be Unique for Each Page?
Having established above what a TITLE tag is then it should be obvious that TITLE tags should be unique. If every page on your website is unique - a good idea - then it follows your TITLE tags should be unique.
How Do Search Engines Use Them?
The search engines use the TITLE tag to determine what your page is about. There's a little more to it than that but assuming you are not trying to deceive the engines - a bad idea - writing them on this basis is a good thing. They also display your TITLE tag as the link text in search engine results pages, SERP's.
Is Size Important?
As ever, some will say not but in fact, yes. Google will display the first 66 (although I've seen 70) characters of your TITLE tag but will cut off at the last complete word in most cases. Yahoo! on the other hand will display up to 120 characters. So the smart solution is to make the first 66 characters read independently of the remaining 54 (120-66). By doing this you are catering for Google and Yahoo!.
Should I Make My TITLE All UPPER CASE?
No. Upper case TITLE tags look naff and spammy and Google et al do not think they are more important if you make them all caps. Title tags should be written using Title Case.
What About Keywords?
Yes, put your primary keywords - for the page, not the whole site - into your TITLE tag. However, make it read well. Spammy TITLE tags will do more harm than good.
What About ***Embellishments***?
Personally I think they are naff and unnecessary but if they work for you then go ahead. I have not read any evidence that they work.
What About Keywords?
As stated the title tag should describe the contents of the page. Using key words and phrases your paqe is using will again help the engines to index your page for these phrases. The phrases used at the start of the title seem to have more influence than those at the end......