Is it possible to filter content  displayed by the  Views module using a regular expression?
Set up a Contextual Filter (previously know as Arguments in D6), they're hiding under the "Advanced" menu of you view. There you can put some PHP code to return a list of arguments.  

Here is an example from one of my views, my PHP code return ID for a field regarding the roles of a user, it returns a string separated by "+" like 1+2+3 which is the separator for "OR" so I can select various node which have these values in this field.


This is the configuration to provide multiple arguments.