The first thing I did when I started using my mac was to download and install TextMate, the best code editor I have ever used. It's really cheap (about 50$) and it makes every single coding session really productive thanks to its bundles. Recently, I had to prepare a keynote to train some peoples to OO PHP and especially the new stuffs came w/ PHP 5.3 (namespaces, closures, etc.).
I really had some fun preparing this keynote :
But to be honest, it was quite a pain to have colorized PHP in my slides. I chose to copy my code from TextMate to a nice website called pastie and then copy my code from pastie to Keynote. Now it's over, Thoas told me about a very nice bundle to copy source code directly as RTF, so I no longer have to use pastie.
If you're interested (and you really should), you can download and install it there
I wish I has known about this before I finished my 50+ slides...
