There are so many calendar scripts out there, but i'm having a hard time finding one that meets my specific requirements.

I want an event calendar that many users will post to but not be able to edit others' events.
I'd like it to be searchable, and also be able to select "display <TEXAS> events only" or "display <COOKING> events only" maybe w/ dropdowns(?)
Ideally, i would be able to accept feeds from iCal and Google Calendar.

If anyone can point me in the right direction, i'd appreciate it.

I want a national community calendar without having to enter every event myself. I do want control, and a way to qualify the members who will be posting.

Thank you extra!