Anyone know of location-aware software?

[EFletcher]

Automobile GPS devices like my nuvi 265W are able to play content at or as one approaches a lat/long point -- "Turn left in 300 metres" or "Arriving at destination". I assume this capability is built in to the navigation SW on the nuvi, and just taps into the content in the device's map data.

I would like to be able to create my own content and have it play in the same way. Does anyone know of SW to do this? (Ideally, the playback device would be a smart phone of some sort, and not specifically for the nuvi GPS.)

[chris]

You should use EveryTrail guides for this (http://www.everytrail.com/guides). In the next version of our iPhone app we will have these types of alerts to let you know if you are getting close to the next point of interest or are veering too far off of the route you are following.