Buy a PSP, watch a few movies and play games... That's what I did on a recent trip to Delhi (with about a 5 hour layover in Doha). The lounges (both first and business) are nothing to write home about, but at least you will have a place to sit down and relax away from the hussle and bussle of the terminal. And for some strange reason, the business lounge is a lot larger than the first class lounge (at least it seemed that way to me).