Today I decided to give php 5.3 a run on my laptop, in particular I was interested to test a closure for the case below.
First of all I am running tests on a fancy Linux Mint where there's no official 5.3 package for php so I took the 'compile way' following the clear instructions from Brandon (thanks!). It has been a while since I compiled php and I must say that debian pre-packaged libraries has made the task quite simple and panicless.