Can any travelers give me some information on accessibility on cruise ships? I understand there are handicap accommodations but not many on most ships. Are other cabins available that are accessible? Is it easy for a handicapped person to get around the ship in a wheelchair? ...and not in a wheelchair? Is it easy getting on and off the ship? Thank you for any information provided.

All the newer ships are barrier free. Elevators will move you from floor to floor and doorways all meet ADA specifications.
These newer ships have barrier free accomidations and they will offer them to guests who do NOT meet the requirements IF no-one with a disability needs them. They will however, move other guests out of these rooms to accomidate people with disabilities.
If you have specific questions, post them here. I work daily with disabled individuals and can probably answer most questions.
In short, people in wheel chairs should have no problems on board.
Since the ships rock in rough seas you would not want to try to sail if you depend heavily on a cane or walker. Another issue is ports that don't have piers. At these stops you must use tenders (small boats to get to shore). At these ports they will still try to get you to shore, but be VERY careful as this can be difficult even if you are not disabled.
Again, post any questions you have and I'll try to help.

On one of the Princess ships, a few years ago, an accident on-shore relegated one of my travelling companions into a wheelchair mid-way through the cruise. I was really impressed with how easy it was to get around all the public areas. As well, crew were expert in the machinations needed to get passengers in wheelchairs on and off the ship. I was very impressed by the attention to this issue.

The only problem we had was in our mini-suite, where there was a step-up required to get into the bathroom, shower and tub areas. There was no way to do this in a wheelchair.

Just returned from trip on NCL Majesty - and I suspect what I observed would hold true for many of the older and smaller ships. (I also work with persons with disabilities). Do not know about adapted cabins - so can only comment on public areas.

Elevators are fine. Buffet area had 1 step, but at least one side (od 2 identical buffets) always had a small ramp on either side of the step. Pool was not accessible - I have seen lifts/chairs, etc at other pools, but this ship did not have that. Casino, main performance/show center was flat. No way to get to top observation deck. All restaurants were spacious enough to wheel into without ending up in someones dinner.

Hallways passable, but would be tight if person required extra extra wide w/c. Several places in commone areas I noticed specially marked accessible bathrooms.

If a person could walk some, the main problem would be distances required - even a smaller ship is big. For shore excursions, ramp was rather steep for a person to wheel on/off alone (about 45 degrees), but certainly possible with assist. However, if tenders were required at a destination, I wonder if they would be accessible.

After you deal with the ship accessiblity issues, also consider accessibility at any destination.

Good comments by all. I'm glad Gail repeated my point about sticking to newer ships. I've been on some old vessels (30+ years old) that even able bodied people had to be careful in. Most of those ships are gone now, but any vessels built in the last 5-10 years or so would be good for you retiredguy. Generally, the newer-the better.