The rss and aggregation format is pretty appealing because it's less of a single point of failure...
It's actually a really really interesting problem because isn't this kind of something everybody on the planet wants?
I personally favor and would like to suggest that as well as ical that also a brute force parsing of the raw rss text is considered - possibly as an additional add-on.
This involves scanning for special reserved keywords or patterns such as "on tuesday january 7th" or the like; with enough of a feedback loop so that people that post events to their blog can see if the aggregator is picking up the salient details.
The reason I prefer that approach is that we've got to start treating these machines like intelligent agents, where they are facilitating ordinary discourse; rather than having to freight around all of the incredibly clumsy form interfaces, database schemas, standards for transport of schematic representation of dates and times and locations ... And they're perfectly capable of doing it at this point. There's a twitter mapping application for example that scans twitter messages for loc: tokens where you can say loc:PDX or loc:94110 and it can map those twitter posts... This is a reasonable compromise; a machine CAN deal with this.
That isn't to say that such an aggregator shouldn't also catch ical or whatever; I'm just saying that it's worth it to also { as a second step } push beyond that and let people simply "speak" and be able to capture a broader spectrum of sources than just people who can publish ical.
I notice as well that clearly such a PDX Calendar would basically be totally packed with events every single day... while tending to favor the "get something running" approach; it's a question of how filtering could be done against it.
Anyway; this is just a great and fascinating problem; it's a real social issue; and it's something that for some reason is just not done well as far as I can see. Clearly somebody could even build a business empire around such a trivial app if they were commercially minded.
In any case... it would be worthwhile to either find the off the shelf solution or to knock together something small that services the need and then extend it...
My own sense is that some of us will probably report back with some prototypes - and/or we'll get together at this upcoming codeathon thing that Audrey mentioned and do it there... so I'm totally looking forward to that.
- a