I somewhat disagree with the recent push to discount Task Killer effectiveness. Definitely the article is true, Android is great about memory management. However, I've found in my experience that Android doesn't always choose to close tasks that I would have chosen, and thus, I prefer to retain some control. For instance, I went a week without a reset or using task killer, and found that when memory got low, Android would force close tasks that I considered important: Messaging, Gmail, and Email. I'd reopen them and be bombarded by incoming emails and sms. Why these tasks should be force-closed before, say, the
Paypal app that I almost never use, I don't know. I had not used the Paypal app at all, but it retained it's position while important services were turned off.
So in short, using a task killer keeps more memory free, resulting in fewer forced-close issues with Apps that I prefer to keep in memory.
...and let the flaming begin.