See Queen Beecon Widget Main Thread and WIKI Click on picture to view video.
The World Cup 2010 QBW updates every 20 seconds with 2 HTTP WGETs from the internet
The Poker Dice Deck QBW updates every 10 seconds, via DBUS method, the 5 Poker Dices QBWs
The Dice QBW updates its shape every 3 seconds and at the same time auto-updates its own position on screen via DBUS method call
The QBW on top center of the screen updates with time/date every 5 seconds
The CPU Frequency QBW on top right of the screen updates every 20 seconds
The Flickr QBW updates every 10 seconds with 2 HTTP WGETs from the internet
The creepy Gyro Accelerator controlled QBW at bottom right of the screen is driven by QBW DBUS Monitor feature which senses the tilt and rotation of the phone
Just to give and idea about the stress put on the phone!
Uhm ... can't say actually ...
These are however very extreme conditions just to stress test memory/resources, mutual interaction and widget robustness.
They are however usually ON with less timer juice and my phone battery still keeps lasting ~1 day with WIFI on, couple of IMs (facebook, GTalk), 3 to 4 10min avg calls + spots, 30min cycle 7 accounts mail check, some agenda browsing, limited internet browsing ~30min/day