where [function] is a string describing the action this page will perform, and [id] is either an int (project nid) or string (project name), why should i have to register this as 2 separate menu items (one with a %d and the other with a %s)?  they're both going to be identical in every other respect, and unless i'm insane, the callback function for both items will be a single function that just checks "is_numeric(arg(1))" and does the right thing depending on what kind of argument it is.