Juozas Kaziukenas has a suggestion for all of those developers (and web applications) out there that are still resting back on their comfort zone of PHP 5.2 - don't be afraid of PHP 5.3, the earlier the adoption the better!
While attending PHPUK conference in London, I noticed how much talk there is about PHP 5.3 and "when to upgrade?", there was even a presentation about that. Because I have been using PHP 5.3 for more than half a year, I decided to share my views on this topic. This topic is very important as the earlier PHP 5.3 is adopted, the sooner second iteration of frameworks can be released (story for Symfony).
He goes through a few of the concerns he's heard about making the move and tries to show things in a PHP 5.3 light and how it can help. He mentions the new features that come with the upgrade, the difficulties of porting over legacy code, package support by some of the major linux distributions and gives a few reasons why you should switch right now.