I don't use a rucksack - if that is the same thing as what we North Americans call a backpack. Husband and self each have a very nifty small wheelie. Don't remember the name and it' down in the basement and I am lazy and it is probably irrelevant anyway since there is an ocean between us. His neck issues and my back issues make backpacks impossible but these wheelies are great.
BUT they are very good wheelies, costing about $200+ each so they would be a great retirement gift. Has big wheels and the mechanism is very light so it does not take up much of the weight. It is VERY easy to wheel anywhere - cobblestones, potholes, uneven pavement, muddy ditches. You name, it I have wheeled it through Asia and Central America plus lots of 1st world countries. It's about 5 years old now and is still in great shape. It has a small daypack zipped onto the front and when I've got it all full easily fits within airline limits (-30 lbs I think but I don't remember, but I never pay extra).
There are backpack straps that fold away - have never used them to date. There is a good sturdy handle on the top and on either side as well as the wheelie handle that pops out of course.
But if it were me I would be looking for one of those new netbooks. They are about $300 here in Canada. Like a small laptop, but much lighter and smaller. They are wireless so you can check email and make internet bookings, view travel info, write your journal ...whatever. That would be a GREAT gift.
I am also hankering after an ipod. Both for music and for storing photos.
I am assuming you have a good camera?