I too am 33 and a web programmer- I am doing my prereqs for nursing school right now. I live in San francisco and I called up the hosptial and found out they have a very rigorous volunteer program at General. I applied- it took a while but now i work once a week in the Emergency room as a volunteer workign side by side with doctros and nurses. its fantastic. I think I am really getting a sense of what nurses do (in emergency medicine).
in short I think any hosptial would be happy to have volunteers they are dying for help. Its a great way to see if its what you want to be doing.