Lying to a Search Enine?

I had an interesting idea on optimization that could destroy the web if people actually did this to a large degree. I don't know if it would work, but I don't see how it couldn't. Here is a basic scenario:

Your PHP File sits here....someone requests it....it gets the browser information.....finds that it is Firefox....sends them a page with the data on it.
Your PHP file is still sitting here.....a request.....it is from the googlebot.....send it a page of keywords and seemingly relevant text to get a higher ranking and ranking for many more keywords.

Now the search engine thinks your page has all these keywords and such and it will direct more people there that it would if it saw the normal page.

Any thoughts?

It's called cloaking.

As Thermit said - they call it cloaking. However the search engines ae wise to it and have lots of anti cloaking measures in place. Do it at your own risk, but do expect to be caught

And if you get caught, you will be permanantly banned.....

Something else that I found that was interesting. I registered a new domain about 4 months ago and pointed it at one of our other sites, not doing any work on it only getting bl's for the other site, it now has a PR 3 100 Backlinks.

When people registers new domains is this a common thing to do? Wait out the sandbox and come the other end with a pr and backlinks.

Google engineers have improved their google bots to see this idea of yours. do this if you want to get banned.

Would it not be considered an affiliate site. The backlinks are to the older domain and not the new one. Not sure how it has happened.

Affiliates are at war with SE.