I just got the MySQL AB newsletter in my inbox this evening and there’s an interesting tool they introduce that will convert existing PHP scripts that use the standard (“old”) mysql extension to use the new mysqli. “i” stands for “improved” – the new extension is faster and can take advantage of the new MySQL features introduced after version 4.1:
The new extension ext/mysqli supports all new features of the MySQL Server Version 4.1 and higher, for example Prepared Statements and support for Character Sets. Prepared statements are a great step ahead, especially nowadays when everybody is concerned about security.
The article goes on to explain that a WordPress installation can be converted to mysqli and ready to use in under 45 seconds. What it won’t do is create things like prepared statments, which of course, is up to the developer!
The full article is located here: http://forge.mysql.com/wiki/Converting_to_MySQLi