50C looks pretty well... Maybe I'm just in the old netbook game too much. My Celeron netbook idles @50C and normally can go as high as 60-70 on load. Not that it can handle much load, anyway.
Though, getting a cooler pad kind of kills the idea of a netbook (highly portable laptop). However, you can set it up at the place you will be using it the most, just like I set the cooling pad for my netbook at work.