If it was given while the father was living it is taxable. If it passed to the son as an inheritance when the father died, it is not taxable unless it is worth over 2 million dollars in 2008. That is the IRS rule. You have to check your state regulations. My state abides by the IRS rule as well.
Do I need to pay a tax as next of kin -only survivor- on a $100000 estate from my brother?
Yes you do need to pay all of the stuff