out of those three, i think the s360 is probably you're best bet. the asus is going to be significantly bigger, and the hp is not as good quality or screen
well as long as you don't use it for intensive games you should be fine. it handles word processing and the like quite well. a couple issues i have heard is that it can get kind of hot and the screen isn't the best. on the flipside it...
aamsel is right. thinkpad does offer excellent accidental damage protection and a great warranty. still, i've heard great things about Asus global warranty and the quality of their laptops. for most people, accidental damage coverage is...