308 Guadalupe Street is the address generally used for a future project at the downtown block bordered by West Third, San Antonio, West Fourth, and Guadalupe Streets. That block, located directly south of Republic Square's snazzy new incarnation and currently only occupied by a parking lot, is one of Austin's last remaining empty downtown blocks unencumbered by Capital View Corridors -- meaning a potential tower development at this location could become the city's next tallest . . .