Anyone in this thread needs to understand one simple thing about the battery life. I am a commercial distributor of virtually every type of batteries there are, from cell/smart phones and laptops, to medical, to automotive or industrial. I see you coming! I love that many people are buying the crap that Google, phone manufacturers, app developers, and "service providers"(many of which are our clients) are selling in regards to Task killers/managers. As a salesman, my family is appreciative. As a consumer who actually uses my phone for business, rather than play, it sucks.
I am an expert in regards to batteries, so please understand this: ATK and other apps are effective in extending the life of your battery. Processes and applications running in the background DO affect the run-time of your device adversely. Your phone battery is designed to last roughly 2 years or a few hundred (300-400) cycles (charges) if cycled properly. The fact is, most ATK users on 2.1 were affected dramatically when the "froyo"/2.2 update took effect. Let me qualify this statement by saying those of us who use the phone for work time rather than "play-time" were more adversely affected. I, and many others, were getting 2-3 days of run-time on a single charge. Since the update, we are lucky to get 12-15 hours. That probably sounds OK to people that use their phones for gaming, etc.
Bottom Line - Processes and applications running all the time are doing so for multiple reasons. The primary reason is battery life. Roughly 71% of retail phone transactions in the U.S. can be attributed to poor battery performance, and do you think the entities I listed above don't understand this fact. Wether the consumer just says "screw it", why pay $50 for a battery when I can just "upgrade" my phone (and sign a new 2 yr $170/mo. contract) for the same cost, or the consumer is told the phone is "faulty" when it's just the battery. Who benefits from this? Not me as a consumer, Not you... (Just look at the group I listed) I pay about 1/6th of what a retail consumer would pay for an OEM Motorola battery... I may not like the fact that I'm being inconvenienced, but I can, and now do, keep a spare battery at all times.
When are you upgrading next and why?
P.S. - I use wireless daily and never vere from 3-G on the road. The same day I "upgraded", I went from 2-3 days of run-time to less than 1. All settings are the same.