At Dragoncon, where the lines for registration are VERY long, I appreciate the fact that I can go to the Disability table, give them my registration information and sit in a chair while someone gets my badge for me. They also allow my partner the same privilege, so I'm not finished with registration and forced to stand around wating for him for several hours.

Another nice touch is the "guaranteed end of row seating" When you walk with a cane, it can be difficult to squeeze past lots of people to the center seats. Most panels I've visited at Dragoncon have reserved seating on the aisles for people with a sticker given to them at disability services. It's a relief to just plop down.

I'll try to think of other things.