I'm a long LONG time BB user, a long time iPhone user, and a part time Android fan. I started using the new Nexus. Two questions.... 1) is there an app kinda like the task manager on the Samsung tablet that can shut down programs? 2) dunno if this is a ridiculous question but is a dark wallpaper less taxing on the batt than a bright one? The phone is great but the batt stinks.
As for your question on task manager, Android is now very efficient at managing your tasks that are running so I wouldn't install a task manager. If you need to kill a task, you can go into your apps settings and close apps if you need to, but again Android is much better at managing running tasks and killing them when needed.
Me personally, I don't think the wallpaper would make that big of a difference, since most of the apps we use have a light background. For example... web browsing, email, messaging, etc.
If you want to stare at the home screen, then you may save a little juice with a darker one.
