I really like the calendar tool. And the snippets code to add them to your own site are great.
A couple of suggestions on data entry.
Beginning and ending time: Do not make these initialized based on the current time. Most meetings start and end on the hour and half hour. Its a pain to change the minutes from 49 to 00 or 30 for each entry.
User-defined event types: Since we have to log in anyways, can each user a have a list of user defined event types....maybe a few standard ones across the board like seminar, meetings, holidays, etc. But I will probably never be entering a sporting event.
Quick links to documentation for each event parameter: IS there a style book for parameter types? I guess it could be added to the wiki, but it would great if it was right on the data form. Like how do I add multiple urls for an event. I might have a url for more information and one for regisiteration.
Jsut a few thoughts to toss around before your meeting