Two Bay area organizations host Halloween get-togethers this Wednesday evening and invite Bay area folks to come festooned in their Halloween best. Swing Time's usual monthly dance event gets a cobwebby makeover with the Halloween Costume Ball at Gulfport Casino's waterfront ballroom. Costumed attendees hop and dip to Halloween tunes, take part in a dancing costume parade and monster Shim Sham, and enjoy spooky treats, candy and other goodies. Costume contest winners take home $100 worth of prizes. Across town, in Clearwater, Stop Pet Overpopulation Together (SPOT) presents a Howl-o-Ween Costume Party for dogs and their two-legged counterparts, who enjoy drinks, hors d'oeuvres and plenty of networking with other doggie-minded folks. Guests are encouraged to dress up — and if you haven't already guessed, this means the doggies, too; a contest will determine the scariest, most original, and best lookalike of each duo. Wed., Oct. 25: Halloween Costume Ball, 7-8 p.m. swing dance lesson/music and dancing from 8 p.m. to midnight, Gulfport Casino, 5500 Shore Blvd. S., Gulfport, $6, www.SwingTime.info; and Howl-o-Ween Costume Party, 6-8 p.m., Bellevue Biltmore Resort, 25 Belleview Blvd., Clearwater, $5 (includes one drink ticket, hors d'oeuvres, and a trick-or-treat doggie bag), www.Barkoween.com.