I use http://doodle.com/ for appointments (as well as it's original purpose of polling a group for the best time for an event). For appointment slots, set the options: "Participant can only choose one option" and "Limit the number of participants per option" to one. No one ever needs to log in to anything unless they want to (for setup or responses). It also has fancy options for linking with calendars, but I've never used those.
This was extremely timely. I just got off a call where I was struggling how our team could communicate appointment availability with a third party. This is a great solution and you don't have to share personal/sensitive calendar information with others.
It regularly takes more than one email when I try that strategy. People don't always reply quickly. I either can't keep all the times that I offered open, or end up offering people very restrictive time ranges that they can't do.
Of course I learn about this great tip a week after I converted all my calendars over to iCloud. Does anyone know of a comparable feature in iCloud calendars?
I'm afraid not, sorry. I've always steered clear of Apple's infrastructure offerings as they don't play well with Google (which is bad as our entire IT infrastructure is built on Google Apps)
