giving house away

I would also get an elder lawyer besides what the above person said and after everything is legal I would let the rest of the family be told by your grandfather and or lawyer.

The tax issue relates to the state in which you live and whatever happens with the Bush era tax reductions. Likely if the house is not valued at a huge amount you are ok. Your grandfather is allowed to gift you up to about 12,000 per year following a process to do so. A CPA can help you with this if you want to get the house now and be forgiven the cost over time. Dependant upon "your family", and if you are not fully aware how they will react to any transaction, will or now, I would recommend that you have your grandfather evaluated to prove soundness by a doctor with expertise to make the decision. Be aware that judging how a family will react when there is money involved is risky. All the best, Chad