After 80 years of life, most men have acquired sufficient household items, tools, and material possessions. For a gift for a person of this age, it is perhaps better to think in terms of services you could do or experiences you could provide to make his life easier and more enjoyable.
A Day Out
At 80 years old, a man's mobility is probably not what it once was. He may be confined to a house or nursing home most of the time. Help him get out into the world and get a change of scenery by giving him a day, night, or even just a few hours out and away from his normal surroundings. If he always loved to fish, rent a boat and head out to a local lake for some relaxing fishing. If movies are his thing, take him out to the cinema. If you have an entire day to spend together, find out what he likes to do and eat, then plan accordingly. Be flexible with the schedule; allow him time to enjoy each activity and be comfortable.
If he's a homeowner, the burden of performing routine maintenance can become difficult, if not impossible. Solve this problem by hiring someone to do it for him. You could find a neighbourhood kid to mow the lawn, a local handyman to do various odd jobs, or hire a maid to clean a few times a month. For elderly men who don't like to sit at home but can no longer drive, hire a car and driver to come once a week or so and help him run errands.
Coupon Book of Favors
Create a little book of coupons that he can redeem to receive favours from you like a drive to the beach, a trip to the cinema, an afternoon of doing home repairs, or a home-cooked meal. Pay attention to his daily routine for ideas on what coupons would be most useful.
Prepaid Debit Card
A prepaid debit card will allow him to buy whatever he likes, whether he's in a store, watching an infomercial, or shopping online. A prepaid debit card is better than giving cash because it offers this versatility. To eliminate confusion, activate the card before gifting it and provide the recipient with the PIN.