Shoudio is an amusing iOS application made to tag places with audio snippets. These can be anything a user imagines, and a lot of fun could be had with this. For example, integrating this into Geocaching could be a lot of fun, allowing things like audio hints to help Geocachers find the cache. However, the developers of Shoudio didn't want it limited to just one platform, so they released a Shoudio API to allow clients for other platforms, and fun mashups.
When it comes to map mashups there's no doubt that Google Maps leads the way. On ProgrammableWeb we list 1,964 Google Maps mashups, almost four times as many as any other API. This popularity makes utilities built on top of Google Maps especially interesting, such as this contextual menu control, which pops up a menu when the user right clicks.
Those worried about whether the internet will kill the local retailers have either a positive sign or another reason to worry. Location-based shopping company Retailigence has announced its first round of developer applications. The apps use the Retailigence API to look for products in stock at local stores, by either keyword or barcode. Brick and mortar retailers have long feared similar technology, which could be used to find a better deal online, where there are not the same real estate costs. Retailigence hope to flip that for local retailers, making it easy for consumers to shop locally.