Searching for a general approach for passing custom lists of node IDs as an argument to Views 3.x
What you really want is a an "argument default plugin".
There are some availible in views itself, one is the php one, which you use already.

It's really not that hard to write. You need the following hooks for it:


hook_views_api
hook_views_plugins


After this you have to create the plugin and most important write a function called get_argument() which returns the arguments.