I'm a fan of categorized tags (tags prefixed with a specific word so they group together in the tag list). It makes it easier to find things if you don't have to scan the whole list looking for a specific location, topic, etc: all the locations, all the topics, etc. are all grouped.

How about these?

"where:"
To be used with anything else to denote location. Like: "where: va" and "where: dc"

"event" or "event:"
For one-time or yearly events. If you have to put it on your calendar, it's an event. Might have to be broken out into areas like "event: music" "event: shopping".

"info:"
For things specific to particular areas: "info: va", "info: dc", "info: md", etc. These would be for persistent things, rather than one-time events (which would obviously use the event tags).

"discuss:"
For things not relating to actual concrete events or places. Like, "discuss: politics" or "discuss: music".

"question"
For folks who are asking for information, to be paired with other tags about what they're asking about.


So from that we'd get:
"What do you think about dc statehood?", tagged "discuss: politics, where: dc"

"Who do you think's the best DC-local band, and when's their next show?" tagged "discuss: music, where: dc, event: music, question")

"What's the best way to get to the Cherry Blossom Festival?", tagged "event:festival(?), question, where: dc"

How's that for a start? :D