The ever present debate on title tags and what is deemed its acceptable face. The agreed wisdom is that the title tag of a document will only be displayed to roughly 66-68 characters in Google. Other engines have their own set of rules. For example Yahoo will display strictly 120 characters.
I blame it squarely on the pixels. Somewhere, someone in each of the search engines has decided that the amount of title displayed in a search result has to be no more than X pixels in length. The number of characters displayed will then depend on the sentence structure i.e. how many double space characters or special characters (like this ? or this &) are used in the sentence will determine when it becomes truncated: 
The people at the World Wide Web state the following
The title should ideally be less than 64 characters in length. That is, many applications will display document titles in window titles, menus, etc where there is only limited room. Whilst there is no limit on the length of a title (as it may be automatically generated from other data), information providers are warned that it may be truncated if long.
Regardless of the vagaries of character length, there is general agreement that your page titles are of huge importance in the whole SEO process. But then page titles have to be looked at from two, sometimes dichotomous, standpoints.
Firstly there is the visual and search results aspect of page titles. Now here is a given: A web title in a set of results is only given a fleeting glance, in that brief encounter you only have a split second to make an impact with the interrogator. The page titles have to scream “Buy me”, “look here” or “your search is over” – that’s a given. On the other hand, as the page titles have such an influence on SEO, then why is it that we have to limit ourselves to the 66, 67 or 68 characters? There is nothing to suggest that anything after the 66th character will be ignored by a search engine. We know it won’t be displayed, but that’s a visual issue, not exactly an SEO issue.
So the best way to see something concrete on this area is to do something. When you create a sitemap for your website and submit it to Google via their Webmaster tools, they very kindly report back any problems it finds. I threw up three pages with elements trying to entrap and entice this friendly service and to see if it reports back any title tag issues. The title tags are 66, 121 and 140 characters respectively.
The page was duly surveyed and the short meta tag was the only issue reported. The page with the largest title had the short meta description, so we know that the page was given the once over. The final part of this experiment was to see if it would index a word contained in the three pages titles. On one page the word is visible, the other page it was not and the final page it is the 121 characters. Its indexed all the pages and actually in search results it ranked the page with the longest page title before the other pages. I am not going to take too much from the experiment. There were other influencing factors here that could have affected the search results.
I would however suggest that clever page titles can be written which allow you to use at least 120 characters and all of those words would be indexed. 
