Apple announced a new in-house app called Find My Friends today as part of the forthcoming free update iOS 5 – and it sounds a lot like what other services already offer. The service will allow iPhone owners to selectively and for a defined period of time share their location on a map with their friends and family. But apparently it’s just for finding other iPhone owners. Who else would you want to find, anyway?

Persistant location sharing on demand is clearly a growing trend, witness Google Latitude, Glypmse and startups like Geoloqi and EchoEcho. What has Apple brought to that party? Maybe improved usability, ease of installation, accessibility for everyday iPhone owners – but also a feigned ignorance about all the other options and all the other phones on the market. Imagine how many more friends I could find if Apple released something that was interoperable with other services and other devices. Just like I can call them by voice. But no…it’s just for Apple Friends to find Apple Family. I love Apple devices, but this is just obnoxious. The time for siloed, single-vendor, location sharing apps has passed.

Seattle-based Glypmse is a little more complicated – but it’s cooler. I don’t expect Find my Friends will let you send an SMS to someone you’re meeting for lunch with 30 minutes of access to your location in transit. Unless of course they are Apple contacts – and who else is there in the world that matters, anyway?

Google Latitude has a world of potential and very similar use cases. I suppose there was no way to expect Apple to build something that would share location across device makers. Sometimes it feels like if Apple could prohibit its customers from calling anyone but other Apple customers, it might do so with a smile on its face.

There are certainly some families where every member has an iPhone – but those families are a little obnoxious, aren’t they? Why do you have to be like that, Apple? Can’t we all please share location together, with whomever we choose?