Using iPad on working is really convenience, there are some really great app help iPad turn to one of the most useful tool. One app I recently download is called "Penultimate", it could let me draw/write anything I want as like writing on paper, then save as a document.
Penultimate on App store Download it
But I used to write by finger, I have to admit that my finger not that thin as a pen, sometimes it bothers me that I have to write words larger & event hard to draw a chat, so I decide to find a stylus instead.
Here is a mini pen I found, it has soft nib like made by rubber, it's so small just a thumb high, can easy put it on aside of headphone pocket.
It cost US$ 14, friendly price, and it's sensitive and really works fine on capacitive touch screen.
This is not the best stylus I've used with laptop, but since iPad is made for mobile, I think this little stuff is good enough.