From my experience in using hebrev text in HTML, I prefer using
<html dir="rtl" lang="he">
over mentioned PHP functions. It works perfectly with IE 6 ... needs some tweaking in Mozilla though.
I found this site http://tlt.its.psu.edu/suggestions/international/web/tips/align.html useful.