ThinkTank Airport Essentials. This is one of the three non-roller bags in the Airport series. That side pocket is made to insert tripod legs, but it will fit a phone, wallet, or 16 - 20 oz water bottle.
Pictured here with a 5D2 + 16-35 f/4, 70-200 f/2.8, 24-105 f/4, 28/50/100 primes, 580EX with Yongnuo YN622 triggers, 5 B+W 77mm filters in hard cases, and 3 battery chargers.
You can also remove the gear from the side column and have enough room to fit a Benro Travel Angel. This is the now discontinued TRAB-069 that folds down to 13.1 inches. There's just enough room left over to squeeze a Tamron 1.4x teleconverter + 12mm extension tube in there.