Aw shucks, RG (blush, blush). But since you were so sweet , here are some more of my travel tips.
Vienna - The Schonbrunn (summer palace) is wonderful, with gardens and grounds as well. If you go to the Schonbrun, then skip the Hofburg. There are not nearly as many rooms on display, and many are similarly furnished to the Schonbrunn (no surprise, same royal couple). Have a good map of the center of town with you (and as above, a compass is handy). I found I got turned around a lot in Vienna - even with a compass. One of the very best things I did in Venice was to get up before dawn and go to St Mark's Square to watch the sunrise. Then I went back to the hotel for breakfast.
Venice - Rick has 4 free audio guides that you can download to an mp3 player. I found them all great. Don't take the Secret Itineraries tour of the Doge's Palace - it will be unbearably hot in July. If you visit the Doge's Palace (recommended), the rented audio tour is quite good. Follow Rick's instructions on the St. Mark's Basilica tour for getting in. Time your visit to be there between 11.30 am and 12.30 pm when the mosaics are floodlit. When the lights go off, you wont believe how anyone appreciated them (the mosaics are outstanding) before electricity. Expect to get lost in Venice (even with a map and a compass) and enjoy it. You won't be lost for more than a short time and the back ways are often charming and sometimes surprising. Don't hesitate go go into any church you pass (Vienna as well), as every one has lots to see and enjoy.