How can Foursquare get more people to check into places as they go about town? One way is stickers. Next month you will start to see stickers in storefront windows reminding Foursquare users to check in and unlock specials. Foursquare’s director of business development Tristan Walker flashed one of the stickers in front of my camera when I was visiting the New York offices earlier today.

Today, Google Earth released a new edition of its desktop app which hikers, runners and cyclists are going to love. They call it Google Earth 5.2. I call it the Hiker;s Edition. One of the new features allows you to recreate the path of a hike or bike ride by ingesting geo-data from one of your GPS devices. The visualizations show you the speed, elevation, and other stats from your hike, which you can see as an animation inside Google Earth.

With a massive membership of more than 230 million gamers, one of the biggest challenges that social game company Zynga faces is keeping up its growth. One of the secrets to its success is the ability to use its existing hits (Farmville, Texas HoldEm Poker, Mafia Wars, etc.) to cross-promote new games and help launch those games. Its other advantage is that so many people now play its games that new games now get free a ton of press and blog coverage.