No gain from caffeine?

I've been sleep deprived for the past week almost. What with the night train (in which they didn't turn off the lights), the short nights, the long drives, the long hikes and a very late return immediately followed by the start of the week, I can safely say I am tumbling towards exhaustion at an unprecedented rate. And how have I tried to combat the overpowering drowsiness through the day - yes, that cup of coffee.. or in my case, those cups of coffees. The worst part? They don't work. Sure when the warm drink cruises down your parched throat, it seems totally worth it. And at that instant you are sure that the drink will keep you awake. Not for me. I've had one tea and 2 coffees since morning and my eyes are dragging shut till now. The only thing that's keeping awake? Blogging. So, here's the second post of the day! Any tips on how to keep awake will be deeply appreciated. Suggestions may not include youtube/chatting/orkutting/FB or any other vetti mantra.