Converting dynamic into 'static looking' urls

I'm listed and am worried about google getting upset when I change.

[eplus]

I've finally got around to playing around with my code and .htaccess file so that one of my clients sites url's will now look static to google and hopefully improve listing the only thing is I'm worried about when would be best to tell google?

The site is generated in php from a mysql database and I'm testing the url to see if it looks static. I.E. www.mysite.com/keyword1/keyword2/pagename . I had to put the .htaccess file in a folder of root as my host doesn't allow it in root :-( so that's keyword1 and keyword 2 is the php page keyword2.php which is my template page. I've use .htacces to force the keyword2 to be treated as a php page. The pagename at the end is just stripped out and used as a variable for the template page so it knows what page to show, anyway I digress.

The thing is the site currently runs as both static and it's original dynamic form www.mysite.com/index.php?page=pagename and these are the results that are listed in google. I want to change over but I don't want to go a month with all the google links not working, on the offer hand I don't won't google to think I'm running two copies of the same site and penalise me. I could build in a redirect on index.php that catches all the old links and instantly gives them the new url but would this be enough to keep google happy?

Any suggestions from anyone with experience of this would be appreciated.
Kind Regards
eplus

[ciml]

It's hard to say exactly what to do, none of us knows what will happen next month (thinking back to about Christmas time this sort of thing was a major problem).

In this situation, I would be inclined to activate the new addresses and /robots.txt exclude the old addresses. I like to see changes at the time of the update (so Google gets the new site for the new crawl) but other people have different ideas about that.

[bcc1234]

Write scripts that just do redirects and place them in the position of the old scripts.
Something like,
domain/myscript1.php?pars=vals
will return a permanent redirect to your new url like domain/myscript/pars/vals
and that script will display the content.

That way if googlebot comes - she will figure out what to do.
And the visitors will be redirected to the correct pages.

That would take at least 2 updates to complete, but it's best to just leave the redirect scripts there in case somebody had a link to one of the old urls.