I wasn't going to post anything about this because I figured it wasn't really worth sharing. But then as I had loaded up the video posted below to watch I actually had someone come in to my office and tell me how they had been told by a Genius 1 at an Apple Store that they should shut down/kill applications on their iPad in order to improve performance.
The bottom line is this, quoting from Fraiser Speirs article that accompanies the video posted below:
...killing apps manually is fine as a troubleshooting step but it shouldn't be part of your daily routine.
That post and the video are a follow up to Fraiser's earlier post titled Misconceptions About iOS Multitasking where Fraiser goes into great technical detail to explain why you don't have to kill apps to improve performance on your iPad/iPhone.
It's not to say that you should never do it. It's just that there's no reason to do it on a regular basis. There are certainly some apps 2 that don't manage their memory very well or situations where an app is stuck/frozen that it makes sense to manually kill it. But it's not something you need to do on a daily/weekly basis to improve performance.
I recognize that since this is the internet, there's anecdotal evidence for anything so, as John Gruber said in his post about it,
Like with any voodoo, there are die-hard believers. I’m quite certain that I am going to receive email from people who will swear up-and-down that emptying this list of used applications every hour or so keeps their iPhone running better than it would otherwise. Nonsense.
Fraiser's Video Demoing How iOS Takes Care of Memory Management For You permalink
Direct link to video