I bought this
clip lamp through dealextreme coz it was pretty cheap (~2.5$). It is ok i guess but it isn't enough to light the hole screen which is a bit frustrating since you'll have to change its direction in every page.
If i wanted to buy one i would buy a "2 headed" lamp like one of these:
price ~5$ which is fine....
Another option would be a casing with a light someone posted about in this forum a while ago.
p.s. I haven't tried these myself, i can't guarantee that the clip would fit on JBL (the one i bought does fit).