Almy, my husband and I (21 years in December) did the Vegas thing too. We told everyone when the date would be, went to the Excalibur, reserved the wedding time, bought tickets for everyone to the Jousting Show for the "wedding dinner", it was non-stressful* and everyone had a good time--and it cost about $500, less than most peoples' dresses.
*The only stressful moment came when his mother, my mother, and his grandmother started arguing about who was going to do my hair and what it was going to look like. I solved that by walking out, across the street to the strip mall, and getting it done then and there on the spot.