Communities get festive, arts show and yards sell all over the place this weekend. A roundup of shows and fests:

Old comic books, movie posters and advertising tins are among the collectibles waiting to be collected, for a price, at the great Mid-Atlantic ANTIQUE ADVERTISING MEMORABILIA show and sale this Saturday 10 to 7 and Sunday noon to 4. More than 70 dealers are at the Montgomery County Fairgrounds in Gaithersburg, and Sunday noon to 4. Tickets are $2.50 for both days (under 12 free) and parking's free.

The eighth annual FREDERICK CRAFT FAIR features more than 400 craftmen from 40 states: they're all doing, showing and selling Friday, Saturday and Sunday 10 to 6 and admission is $3 (under 12 free, as is parking). Saturday John Hartford plays, and Sunday it's Doc Watson, in shows at noon and 3 both days.

It's Lower East Side New York, a look at the area where early 20th-century Eastern European Jewish immigrants lived this Sunday 2 to 5 at the JEWISH COMMUNITY CENTER in Rockville. Street games, exhibits and crafts are part of the free afternoon at 6125 Montrose Road; the knishes and egg creams are extra.

See and buy at the CERAMIC SHOW at the Vienna Community Center this Friday 4 to 7, Saturday 10 to 6 and Sunday noon to 6. Area professionals and hobbyists show their works, and supplies are for sale for would-be ceramists. Admission is $1 at 120 Cherry Street in south Vienna.

The SILVER SPRING COMMUNITY FESTIVAL is Saturday 10 to 3 with a yard sale, foods for sale and music. Free admission at the Silver Spring United Presbyterian Church, 580 University Boulevard East.

St. Peter and Paul's Church sponsors its first MID- EASTERN FESTIVAL and fair, with Lebanese/Syrian food for sale, a moon bounce and a dunking booth: free admission Friday 3 to 8, Saturday 11 to 8 and Sunday 1 to 7 at 7108 Bradley Boulevard, Bethesda.

In historic Frederick, Maryland the annual ART IN THE PARK arts and crafts show is Sunday noon to 5:30. The demonstrations and sales by artists from a five-state area are at Second and Bentz streets across from the Old Maryland National Guard Armory. Free admission; call 301/874-5150.

Laytonsville, Maryland hasn't changed much since its earliest days, except that then it was called Cracklintown and wasn't having a 90th BIRTHDAY PARTY. It is this weekend, and there's a parade, music and crafts for sale as well as a festival and hot-air balloon launch. All free.