It's a little late for Valentine's day, but the USCCB has a fun resource for couples over at its For Your Marriage site - ten fun ideas for cheap dates for you and your sweetie!  I'm personally lovin' #6 - "Evening at the Ritz" - we used to do this when we were dating and couldn't afford anything but a cup of coffee in fancy hotels.  The list brought back fond memories!  What's your favorite?