Know-How Exchange : Just for Fun

I've had great success by creating community geocaching events. We lay out caches specifically for the event, rent out GPS units, and have a point system. Local companies donated awesome prizes, too.

If you're looking to go a little higher-end (your target audience wouldn't like traipsing around town/the woods with a GPS), my local community college did an awesome event where they partnered with a limo company and did a scavenger hunt - you had to have a carload of people and could purchase different packages (champagne, caviar, etc.) inside the limo. Local companies donated some awesome prizes.

You can also do a poker night where there are different places around town you can find a playing card; the person/couple/group with the best hand at the rendezvous point wins. I've seen this done on motorcycles or in cars.

I know you mentioned auctions as becoming stale but have they held "Chinese Auctions" which are a little more interesting than a straight auction.

Here's info on Chinese Auctions:
https://en.wikipedia.org/wiki/Chinese_auction

Not sure what you're raising funds for, but

Bricks and Pavers engraved with donors acknowledge with name or special message engraved.

Murder Mystery Parties

Evening with the Chefs...music, samplings of local restaurant faire.

Doggie Parade with dogs decked in costumer and sponsors sponsor miles completed.

Golf Scrambles

Purchase trees and benches in local parks "In Memory Of..." is a great way to beautify your parks and raises funds for doing so.

The list goes on and on.

Marketing-Riot

One way that has worked is to have a local hero (someone who has made it really big) in town for an autograph session. Sometimes you have to dig pretty far back. Remember when Jim Hart was QB at St. Louis?

Like that...

Michael

Completely changing a gala into a casual event and getting the same participation is difficult. Maybe you should consider still hosting a social event, but changing it to be more funky and fun:

Black & Blue Ball where people can wear black tie to blue jeans (or Denim & Diamonds works similarly), then have a fun band play and offer cocktails and heavy apps instead of a stuffy dinner.

Change it into a wine and food tasting theme. Local restaurants donate all the food and wine for a chance to show the community what they've got.

Good luck! I did fundraising for 6 years and miss it!

A casino night might be fun. There are places that will rent the equipment and staff some of the games. You can allocate chips to each individual and then have prizes that were donated that could be traded for chips. You could even make it so that people could donate their chips to particular causes. You could allow people to buy in for more chips.

Close off the downtown street, set up the gala on the street itself, and keep the local stores open. People will be able to shop, eat, and have this private village open for just them.