One usecase that I find myself usually is Gpodder updating/downloading in the background while I'm watching something on KMplayer;

Another usecase is having multiple leafpads opened with one or two fileboxes editing something;

The filebox case is usually together with, if I'm editing some .sh's, Opera with some tabs open while I search/copy/paste commands between all of them, + a lot of x-terminals cd'd each in a different folder;

Also when I'm waiting something between classes I might have some leafpads + xterminals + easydebian running gimp editing something;

Also the added bonus of being able to halt all these and start and close htop or wifieye or conky in order to see something and being able to close that and be able to come back and see all your apps waiting there the way you let them.

Of course, but this should go without saying, if kmplayer is not open I'm listening to music with the stock player, but this I don't even count.

Yeah, sometimes it gets sluggish, but right now I'm fairly used to it, in a way tat I can predict and avoid most of it or like when I press some command I already know where the popup will open and I already clicked where the command button would appear. Another good thing while running 4+ thing at a same time is to lock the phone to landscape. And I can always have the extra push of oc'ing to 1ghz (actually my phone is either on 1ghz+lvl5backlight when I need performance or 500mhz+lvl1backlight when I need battery - but then again another thing that I LOVE about my n900 is that I can replace batteries when needed, and I carry up to 4 on top of the one on the n900 giving me a minimum of 7,5hs of whatever[film/n64/internet] when I'm traveling).

Maybe is that I'm not really used to android, but I cannot for the love of me figure out how to even START to do that on my android. Yeah, it is an old motorola droid running android 2.1.2 cianogen mod, but I only have it for the sake of banking and angry burds, and not even that it is doing right (bug of already own a thing that has failed to buy).

That's all!