Tom has written about the treatment of IT / it in the search engines before (it is hard for search engines to distinguish between 'it' and 'IT' when searchers never capitalise things correctly!). Since one of our clients provides IT support, we spend quite a lot of time looking at the results for various IT-related searches and so I have another oddity to share.
In general, when you carry out a search on the major search engines, they highlight the words and phrases from your query in the titles and snippets of the results. In the case of paid search, your search words are highlighted wherever they appear in the advert and URL (among other things, it is this that makes dynamic keyword insertion - where your search query is used automatically in your advert - so powerful).
If you take a real look at a search results page, you will see that this is a very powerful effect drawing your eye to any mentions of the search phrase you used. While the paid search results are carefully crafted to include mentions of the search query, the natural results also tend to (as a result of the relevance element of the engines' algorithms, and also because they select the snippet they display in part by finding parts of the page with the query string).
Now try a search for it support (google, yahoo, live). Yahoo! gets it pretty much right (as Tom said on his post, they seem to have cracked this particular problem quite well). Live is bumbling along with a clue (apart from the paid results, those look like 'support' results to me (including requests for support for charities), not 'it support'. And Google is interesting:
See the difference between the highlighting in the paid and natural results?
Paid search has realised that IT support is a phrase whereas while the natural results are relevant to IT support (they haven't got the same issue as Live whereby they effectively discount the 'IT' bit), they aren't highlighting the whole thing as a phrase, but rather just highlight support: IT support.
It's a tricky problem, and also opens up a whole load of interesting questions as soon as you start thinking about it in a bit of detail...