I'm afraid your question is almost too vague to answer.. but if he needs access to the money he is probably limited to saving in a deposit account rather than investing.
If he is internet bank-adverse (as many older people are) and does not want the hassle of drip feeding into high-interest paying regular saving accounts, I would recommend Anglo Irish Bank's 30 day notice account which pays 4.5%. It's not a bad rate on his money until he decides what to do with it. Remember also that over-65s are entitled to a rebate of DIRT but this will depend on his current level of income.