An app note(PDF) on smart on/off controller and voltage monitoring chip from STMicroelectronics.
These devices allow easy and safe control of applications run with one or two push-buttons by securely starting or powering down a system and also resetting the processor or disabling power in case of a non-responding application (e.g. code in a dead loop). This makes the STM660x devices suitable for a broad spectrum of applications such as terminals, audio and video players, smartphones, PDAs, PCs, or any portable device.
Interesting, got me inspired for a second, but quite easy to do the same with a $0.60 micro which is also better if if you are making in qty or want more package options such as SOIC8