Can I use 3G network on my Android 2.2 tablet?

What is your tablet? Go to any carrier(I would personally choose Verizon Wireless) and ask them if they can hook you up with some 3g. Verizon is adding tiered data plans soon, and if you get unlimited now, the contract will carry on into the future, so you get to keep your unlimited data plan instead of going into tiered. The cheapest data plan is for 2GB, and costs as much as unlimited now.