From you question, appears that you want to setup the iPad 2 via 3G as a Wi-Fi Hotspot to allow you other devices to connect - correct?
Now, I do not have 3G on my iPad 2, so not an issue for me, but I would suggest checking with your cellular provider (and/or their respective website) to determine if this is a possibility (which if so will cost you extra) - good luck and let us know your results - may help others!
And hopefully others in your situation have already addressed this issue and will respond - :thumbs:
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.