I have been to Tirupati only once. We went directly to the temples and came back. My friend Sujatha has an article in The Hindu in which she points out other places of interest near the temple town.
The Akash Ganga waterfall, 3 km from the temple, that the faithful believe flows from the feet of Lord Vishnu, is a huge attraction. Situated on the Tirumala Hills, Sila Thoranam, a natural rock formation, is a wonderous sight. It is a naturally formed arch of rock, the likes of which are reportedly found only at two other places in the world