That will only confuse readers. Establish the language and terms you are going to use in your navigation approach, and use them consistently throughout each page of your Web site. Think about it this way. You visit Dublin city center regularly. Your favorite clothes shop is situated on Grafton Street, which is right beside Trinity College.
People are, by nature, habitual and conservative.
If every couple of months you change the structure and navigation of your Web site, you risk alienating your regular visitors who have gotten used to your previous navigation and structure. Gerry McGovern is publisher of New Thinking, a newsletter covering web publishing topics. Spark discussion in ClickZ's Forum. Voice your opinion. It's hard not to stick with it.