Chinups definitely help develop your biceps, but it's primarily a back exercise and you want to avoid using your biceps too much. If you have a proper training regimen and are working your full body, there are many exercise that will help develop your biceps, but the work you do specifically for your biceps (curls of various kinds) are what will really give you the results you want.
BTW, the reason I've advocated EZ bar curls and not straight barbell curls is because I find straight barbell curls tough on the wrists, expecially at higher poundages. IMO, the EZ bar is much easier on the wrists but achieves the same results as a straight bar.
MickeyKnox:
I tried those curls you posted during my last bicep workout and they're great. I will definitely add them to my repetoire.