In only two years, the Summer Strut Home Tour, which takes place in early June, has leapt to the top of the list in this otherwise moribund category of entertainment. After all, how long can you really stay interested in Swiss Avenue? Sponsored by the AIDS Resource Center, the Summer Strut so far has presented tours in the Turtle Creek area and Greenway Parks, west of the Dallas North Tollway at Mockingbird Lane. It's not cheap--$50 a head and $90 per couple--but there are hors d'oeuvres at the houses and often live music. Old homes are mixed with new in a blend that is more stylish than what one sees on typical neighborhood tours.