Foursquare, Gowalla, Instagram: Mobile photos are everywhere

It’s been a big week for numbers about photos. Yesterday, location-based service Foursquare launched the latest version of its app with support for photo-sharing, and chief executive Dennis Crowley said later in the day that the service was already approaching one photo uploaded per second. Competitor Gowalla said today that its users have posted 1 million photos. And mobile photo app Instagram also said it has hit 1 million users.

My first thought upon seeing those numbers: Damn, that’s a lot of photo-sharing. Instagram in particular seems to be growing super-fast. The service only launched two months ago — in comparison, Gowalla still hasn’t hit the 1 million user mark (at least, according to the latest numbers I’ve seen), Foursquare took more than a year, and Twitter took two years.

My second thought: Gowalla better get moving on deals with other photo services ASAP. As TechCrunch’s MG Siegler notes, a lot of Foursquare’s fast pickup on photos probably comes from partnerships with Foodspotting, Instagram, and PicPlz. Meanwhile, services like Instagram and PicPlz pride themselves on integrating with lots of other services.

At this point, with all these integrations already in place, none of these apps can try to differentiate by “owning” your photos. Unless you’ve got a massive user base like Facebook, the name of the game is making it as easy as possible for users to share photos on whatever site they want — that’s probably what investors like Andreessen Horowitz and Benchmark Capital are betting on.

I think the folks behind Gowalla know this too, since they’ve already demonstrated an open-minded approach to integrating their check-ins with Foursquare and Facebook Places. On the photo integration front, however, Foursquare got there first.