I don’t really have to write a lot about the fact that people continue to have fun by taking advantage of their cities with the help of technology. The return of the annual Come Out & Play Festival this past weekend and Newmindspace’s ongoing popularity prove it pretty well.

Brands are doing a pretty good job lately of releasing location-based services that manage to fit who they are and what they offer to people. To take it up a notch, I’ve been noticing a few that have been doing cool stuff with an already-existing service – yes,Twitter, bear with me – combining the nature of their product with our appreciation of location-based fun.

The first I noticed was Cupcake Stop, a truck that travels all over NYC to sell – yup – cupcakes.

[photo: roboppy]

Cupcake Stop’s Twitter feed had hundreds reading before it even officially launched. During their “beta,” they tweeted to test out routes, give previews of what flavors would be available (including an “invent our new flavor” contest), and let people know when and where they were baking. It was like a Krispy Kreme’s “Hot Now” neon sign on steroids.

Another food truck that did something like this is NYC Cravings, which sells Taiwanese meat and rice dishes. They park in a different spot every day, post their schedule online and use their Twitter feed for spur of the moment changes in plans and location prompts & reminders. Both Cupcake Stop and NYC Cravings leveraged the fact that they are mobile with a tool to help bring more people to them in a fun way.

Brands-who-move-around aren’t the only ones who can do things like this, either. Handbag designer Rachel Nasvik created quite a stir over the past couple of weeks, when she hid 90 of her designs in secret spots all over the city and tweeted clues about their whereabouts.

Followers of this bag scavenger hunt feed (which has over 1,000 followers at this point) ran all over New York, from ATMs to public bathrooms and even our neighbors Van Leeuwen, to try to get their hands on one of the bags (which were also filled with goodies like cosmetics and keychains).

[photo: thrill of the chase]

The fun and inviting “come and get it” attitude was a great way to leverage the craziness that “time sensitive + limited availability” does to people. She definitely got more press than she would have with a more traditional giveaway; the event was covered by Daily Candy, NBC New York, Creativity Online, and Beyond Madison Avenue.

It may seem counterintuitive these days to think that it’s good for a brand to make its consumers come to them, instead of the other way around. But the creative use of a nimble platform and a bit of fun changes the game completely.