Twitter tagging ideas for Grass Valley, Nevada City, Nevada County

I would love to be able to pull in tweets (i.e. Twitter entries) from&about our community - after Marsha's intro and playing around with it myself a little, I think Twitter or the like is the way of the future.

But I want a local Twitter "channel" that's ours, that's more focused than the low-value-to-us chatter that characterizes the location-names-based Twitter search (which gives stuff like "New hat, got it in Nevada City")

And there needs to be a way to find what hashtags our community is using
(Explanation, for twitterilliterates: a hashtag is a term that starts with "#", e.g. #gvnc - all tweets that contain it become part of the discussion - if you search Twitter for that hashtag, you can see the conversation, and if you include it in _your_ tweets, you join the conversation.)

..since if you don't know what hashtag is being used, you can't hear what others are saying, which is sad and inefficient.
A real-life example: after the (Lance Armstrong) Nevada City Classic last weekend, C. suggested that racegoers elsewhere on the course, who were out of earshot of the announcer, really would have benefitted from someone Tweeting the announcements. And perhaps someone was - but unless you knew who, or what hashtag(s) they were using, you wouldn't know how to receive the info. Wouldn't it be nice if we could just go to one page to find out what hashtag was being used for an event, or to meet a need?

I'd like to suggest some tags that we could use, that I think would work well for the community. If you have feedback and/or a better/alternative way please, please share it. (Zuri and Marsha, this likely means you.)

#gvnc for info of community interest. There are no Tweets using this hashtag at present, so it'd be all ours (Since "nc" is also the abbrev. for North Carolina, #nctweet (the previously-suggested tag) wouldn't necessarily stay just us...)

Maybe...
#gvnc #tag both, for a tweet that proposes or announces a community-related hashtag that you'll be using?

#gvnc #biz for business-related tweets, so those who just want to see noncommercial entries can do this (by searching for tweets that contain #gvnc but not #biz) and those who want only commercial entries could do that, too.

Also, when & if #gvnc Twitter traffic should increase to the point that we need to segregate further, we could also do:
#gvnc #news
#gvnc #events
#gvnc #lost
#gvnc #found
#gvnc #wanted
#gvnc #forsale
#gvnc #free
#gvnc #realestate (in place of #biz)
(It wouldn't hurt anything to use these extra tags now, but it's not needed.)

A question for Zuri, Marsha or anyone else who's not a Twitter newbie like me - does it make more sense to do dual-labeling (by which I mean "use two hashtags" - eg #gvnc #biz), or would we just want to have a "gvnc" prefix for all our hashtags (eg #gvncbiz) ?

(The answer, I think, would depend on whether it's possible to do a search for "all tweets containing a hashtag that starts with #gvnc" - but I don't think it's possible, or at least I don't see a way to do this from Twitter Advanced Search - so I'd lean toward "use two tags".)