Post/Calendar plugin that allow for varied multiple dates and date ranges.

I have a client that wants to manage a number of trips that they offer on their WordPress website. Some of these trips may be on a single day, some may be multiple day (a date range), and either one of these might occur multiple times.

Something like this:
Off to Italy: 7/3/11 – 7/11/11, 09/10/11 – 9/18/11
Around DC: 8/5/11, 8/23/11, 9/21/11
Spring Fling: 5/1/11

What I was wanting to do was find a custom field plugin that was flexible enough to add any number of dates and date ranges.

Then I was hoping to find a calendar plugin that would display these in a visual format.

I’m using posts so that I can organize the trips by category and then create list pages that show up in the menu automatically and allow visitors to drill down to trip details (the post).

If anyone can point me to plugins that can get me there, I would greatly appreciate it.