Calling our wedding budget shoestring would be considered flattery. My fiancée and I, however, have managed to lower our costs by making our wedding writing themed (we're both writers, and it's also how we met).
One of the things we're considering doing is using butcher paper (or some other inexpensive, rollable paper) for table covers and providing a bucket of pens/markers/etc. on the tables and encourage guests to write quotes on the table coverings. Supposing any of the "tablecloths" survive the wedding, we'll use them for parts of unique, craft decorations around our apartment to remember the day.