Quite a few people use Twitter as a resource for restaurant and nightlife suggestions during business and pleasure trips; a party promoter or restaurant owner trying to drum up business for the weekend could monitor tweets tagged with a specific locale and keyword and send drink tickets or meal discounts as @ replies.

There are the inevitable hurdles if Twitter really is laying the groundwork for some sort of geotargeted ad platform, though. First, the company needs to get Twitter Search up and running much more efficiently than it does now (a task for Doug Cook to tackle) so that advertisers can feel confident about the quality of their keyword search results.

Then, there’s getting enough people to want to reveal their exact locations to complete strangers to create a scalable amount of local ad impressions. (Apps like Brightkite already let users do this, but again—scalability is key). Google, for example, faced a privacy backlash when it rolled out Google (NSDQ: GOOG) Latitude, a mobile app that also shared a user’s location with their friends (also an opt-in).