> Users might also like to use the latest features in PHP5,
> but the host may still be using PHP4.
>
> Hosts might also be running with register_globals on. As
> reported elsewhere in the comments on this site, when
> some hosts turned it off, they got several emails about
> broken scripts. So the hosts simply turned register_globals
> back on.
> The only solutions, besides pestering the web host to
> upgrade, are to change to a different, more modern
> host, or consider renting a virtual server where you can
> set up PHP yourself.
Another solution could be that the web hosting firms would run a new (virtual) server when a new major PHP version is released. The new server would have all security related settings turned on. This way new customers would automatically get the new features and old ones could ask to be moved. All clients would be informed about the possibility to update, so that the not-so-active web masters could start their slow transition process in the following months.
There is of course a downside in this solution too: web hosting firms would need to maintain several PHP version. One way to solve this would be to limit available php versions to two. If for example the host has php4 and php5 servers and then php6 is released, php4 users would be forced to move to the newer version. A major php releases come out once or twice in the year(?) That would give 1-2 years for the slow web masters to adjust ;-)