[Nexus S Themes and Apps] lvnatic:
I agreed that android doesn't need task killers when I owned the HTC Desire, which trully had 512MB RAM, but the Nexus S' RAM is eaten a lot by the GPU and the other radio hardware in the phone. Specifically, 200MB are taken away from the begenning and we never have access to it. So we're left with 300MB of RAM for the OS and the apps, which is extremely low for a high end device. My phone has 113 apps and there are a lot of them that are running their services since startup.

Here are a few tweaks that solved my problem:

1. Download auto memory manager from market.

Its an app that still lets the android OS to automaticly kill background services when you need memory but the limit is set by you. The default limit is 20-24MB, so when your phone has less RAM then those values, it will start terminating background services which aren't needed or haven't been used in a while. I found that value to be very bad for usability. Sure, the OS still frees memory when you need it, but let's say you open a demanding app (a game for example) and you curently have about 30MB of free RAM, android does indeed kill services to free memory for that game, but until it does that the game will be very very very laggy. I'm sure some of you experienced this with some games, that it ran very laggy for the 1st few seconds, maybe more, and makes the phone totally unresponsive.

But with this app you can set the limit yourself. Here's my setup:

a. leave the foreground and visible application untouched (5 and 12 mb) and the secondary server also untouched (should be 16mb)

b. set the hidden application to 60mb (these are background services)

c. set the content provider to 50mb

d. set the empty application to 80mb (you can set this as high as you want, these are apps that haven't been used in a while and are the 1st ones that android kill when you run out of memory, and they do not auto restart)

I find this setup to be very stable and very friendly with the battery. In fact, the battery seems to be lasting longer then it did before.

This way, demanding apps have the necesary free RAM and run very smooth from the begining.

2. I recommend autorun manager (market). It gives you a list with all the apps and services that start when you boot the phone. Now you might choose what ever you want, the ones I disabled on my phone are maps and yahoo apps (mail and messenger) since they are always running in the background and I almost never use them.

3. On CM7 or MIUI ROMs you have the option to kill an app by long pressing the back button, which is very handy and usefull, but used with auto memory manager might be too much. SO I only recommend to use it to kill the browser app (all of them), as they proved to be the biggest memory hogs on my phone. Be it stock browser, opera, dolphin or skyfire, they all eat at least 30 mb, even after you aren't using them. So if you know that you won't be needing the browser shortly, just kill it.

These are the tweaks I'm curently using on my phone and I always have at least 70MB of free RAM. I find them to be very stable and friendly with the OS and the battery as well. Like I already said, the battery is lasting longer for me and the overall usability of the phone seems to be much more smoother.

Pardon my English as it isn't my main language :)