Flash is a battery killer on mobile devices. On my desktop PC I don't have to worry about it as it's always plugged in, but on my laptop (Macbook Air) I use click2flash so I can view flash content only when I want it to show up (saves battery life).
http://www.pcworld.com/article/209856/dump_flash_get_2_extra_hours_of_macbook_air_battery_life.html
"Ditching Adobe Flash on your Apple MacBook Air can extend your battery life by two hours, according to reports. Chris Foresman at Ars Technica discovered battery life in the new MacBook Airs is 33 percent longer without the Flash plugin installed. According to his tests, having Flash installed shaved two hours off the laptop's battery life."
http://news.cnet.com/8301-1035_3-20027131-94.html (about the RIM Playbook)
1. The PlayBook supports Flash, and Flash is a resource hog. Says Wu, "As seen in recent tests for the new MacBook Air, use of Flash can cut battery life in half....From our understanding, the poor battery life of early PlayBook units may be due to its incorporation of Adobe Flash."
http://www.pcmag.com/article2/0,2817,2367542,00.asp#fbid=44EFj9EwkLG
Improve your Android Phone's Battery Life:
Disable Adobe Flash. Being able to run Adobe Flash in web pages is a great, but it consumes battery life. If you have Adobe Flash installed on your smartphone, by default it's set to load every piece of Flash content on every web page. It's possible to change this so the browser only loads Flash when instructed to; open the browser, hit the menu key, go to Settings > Enable Plug-ins and set it to On Demand.
http://www.guardian.co.uk/technology/2011/apr/27/motorola-xoom-review-tablet-computer
The Xoom does well – it achieved as much as the iPad. Ten hours, more or less – although note that Flash will halve that. You think you don't spend all your time watching Flash? If you open a lot of commercial web pages with adverts or (of course) watch YouTube, you're hitting Flash. More on this later.