A couple of ideas: (1) If your guild has a charity program such as Project Linus (kid's quilts) or Quilts of Valor, have a meeting for sewing quilts for the charity. You could have people cutting fabric, others sewing, some people pressing, some binding already quilted quilts, some sewing on labels, some preparing kits for future quilts. Basically everyone can do a "job" they are comfortable with.
(2) Do you have a 4-H or Girl Scout troop in your community? Invite the kids to a guild meeting (good for summer meetings when the kids are off from school) for a one-on-one sewing/quilting day with guild members. Teach the kids how to cut fabric, how to sew 1/4 inch seams, etc. Make a small project, like a mug rug, that the kids can take home.
(3) "Open Sew Day": guild members bring projects that they are working on and do it during a "meeting". Encourage members to bring projects that they are having difficulty with or just don't like. It is amazing how other member's input can help solve problems or help someone "look" at their unliked project differently.
(4) Quilting Scavenger Hunt: done both outside a meeting and at the meeting. A week or so prior to your meeting, send members a list of quilt related items (maybe 25 or so). Members have to gather as many items as possible and bring them to the in person meeting. Part of the rules are that members may not buy anything in the time receiving the list and the actual meeting (yes, some will do it anyway) to fill the list. Items should be small and easily transportable. You can do something like: "take a photo of a vintage sewing machine" (no downloads off the computer allowed!); take a photo of your favorite person using one of your quilts: gather five 5" purple squares of fabric; ten "wonder clips"; the pattern you bought and now second guess yourself (the why did I buy this factor); etc. Make sure the items are varied and that some are commonplace and others maybe much harder to find.
At the meeting, the person with the most items found from the list wins a prize. (You can have more than one prize - 1st, 2nd, 3rd; Most Unusual item, etc.). You can also "sell or raffle" all the items gathered to make some money for your guild.
Hope these ideas help.