spi, tuples

    Greetings, Is there any way to have an spi function return the result of a query, or 
to connect two tables in a view?  Specifically, I have a table of times and locations from an 
aerial flight, and a table of images from that flight, and I would like to select the images 
that occur within a specified area.  I had thought to join two tables in a view which I know 
that you can do with other databases but I cannot seem to determine how to do it in postgres.  
Alternately I had thought to use an spi function but I do not know how or if I can have it 
return the result of a select statement of more than one record.  The database ins Postgresql 
6.5.1 on a Linux (RH 6) box.Any help would be appreciated.Collin Lynch.