If you use any sort of limited/paid data plan, I'd recommend installing 3G Watchdog (https://market.android.com/details?id=net.rgruet.android.g3watchdog&hl=en h

If you use any sort of limited/paid data plan, I'd recommend installing 3G Watchdog (https://market.android.com/details?id=net.rgruet.android.g3watchdog&hl=en https://market.android.com/details?id=net.rgruet.android.g3w...). It gives you instant access to usage statistics, and also extrapolates current usage towards your current (monthly or whatever) quota.