I don't know about your friend's situation but when our 22 year old son was diagnosed we received several helpful gifts. Because he was still really just a kid, he had no savings to speak of - we're covering the deductible ($$$$ because of out of network). There's also the cost of traveling to and from appointments (300 miles each time, gas+tolls+parking+at least one meal= $100 a trip). And paying our son's bills while he was unable to work. Gifts of money, gas cards and gift cards to a discount store really (really, really, really) helped.
He was also given gift cards to a local video rental store. That was great too - we watched a lot of movies while he was stuck at home recovering.
To be honest though, the cards, the letters, the phonecalls, the visits, the e-mails, the prayer-lists, while not tangible items -- these were all precious to us too. As long as you let your friend know you care and are concerned about his recovery, you will do just fine.
darcy (Matt's Mom)