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Should be able to root your phone and once it's rooted download wireless tether (pretty sure it's on the market) and that's it, but it has to be rooted.
if you can tether your phone to your comp already, you should be able to create an ad-hoc, and share the internet through your laptop, further more, if u can modify the default path on your router(most stock fw's won't allow this, probably have to flash dd-wrt), you can share your tetherer'd wireless to your router, and all your devices can use your phone for the internet, whils't still connected to a router(assuming your near a router)