SFO is a hotbed of foursquare activity. Creative Commons image by Håkan Dahlström.

With the increasing use of mobile applications such as Yelp and foursquare, it’s becoming possible to pull ideas from thin air. Users of these apps can leave tips for others to find that are linked to a specific location.

In most places there aren’t enough tips yet to make filtering an issue. San Francisco International Airport, with more than 57,000 checkins on foursquare, is an exception. It offers a glimpse of what we can expect as these services become more popular. The airport is the perfect petri dish for tips: it serves a technically savvy audience and people often find themselves there with plenty of time on their hands.

The SFO tips page contains dozens of notes including places to eat, complaints, ground transportation, wifi and power availability. Mixed in to all of this are ads, other spam and random observations. Some examples:

have a corned beef sandwich at max’s if you’re flying southwest. the best! well, really good

When you enter short term parking do it as far to the right as you can (lvl 2) & then immediately head to lvl 1. There is always parking next to gate and that is the lvl that connects to the terminal

Free wifi at the Continental lounge in Terminal 1- be warned, it’s located outside Security

Smoking hot brunette woman at gate 20. Stop by and smile at her. She is so lovely!

Bart to Millbrae gets you within 1 block of an in n out burger. Great for 3+ hour layover!

Heading to wine country? Take a moment to stop by St. Supery in the heart of Napa on Hwy 29. Mention this to get a 2 for 1 tasting.

Sorting through the volume of tips can be overwhelming. As the volume increases, we’ll need ways to filter them. Among the ways to filter:

• Timeliness. Some of the tips, such as wifi at the Continental lounge, are evergreen. Others, like the smoking hot brunette are very timely. Tipsters should be able to flag their tips to self destruct. As I wrote earlier, being able to identify tips by timeliness would allow for new applications, such as sharing rides. (“Anyone want to split a cab to Moscone?”)
• Social network. Among the tips were tips from people I follow on Twitter, including Danny Sullivan and Adam Lasnik. Being able to surface these would increase relevance.
• Ads vs. not ads. Sometimes people want ads, especially if it can save them money.
• Keyword search.

Places like airports are especially complex because they’re really collections of places, sometimes with other groupings and physical restrictions. Being able to filter tips by terminal would also be useful. But then maybe that’s best left to GateGuru.