It would be nice, if some 'future-thinking' group od PHP developers will convert all, for example string functions into String class. I mean, that for example instead of using strpos($mystring, "b") it would be nice to make it: String::pos($mystring, "b") or to create Java-like objects, so: $mystring->pos("b") will be the best.
If functions will be used, then should be imported, like in Perl or Java: import(::String). Of course, you can use pos(), but now take care about current package and it's function pos(), like in Perl or Java.