You mean run them as part of a server on a pocket pc? Doubtful. If you mean use a pocket pc to connect to a server that runs php etc then yes.
I have seen it done.... I think it was an e107 fan (or some other CMS), they got apache, php, mysql and e107 running all on a pocket pc, bear in mind it was SLOW AS HELL but yeah, it can definatly be done. This was a few years ago im sure, back when the colour screen versions were becoming affordable, so maybe it would run better on a brand new one. I wouldnt suggest it though.