Great use of a tandem.
My friend is blind and we have been riding for about 15 years together. A good place to find tandems is on Craigs list, you will save a bundle there as not to many people want them. For the handicapped, I find that riding a tandem is a great way for them to fellowship with the sighted world. In many ways they are restricted in their activities, but this allows them to break a few of their chains.
Repairing a tandem also introduced me to the joy of bicycle mechanics. The first few tandems we got were beaters, and I patiently dug into them and learned what it took to get them to run right. Yeah, a little more difficult then the single bikes, but for some of us who enjoy the challenge, very worth it.
What a joy.