Digital hot spots allow a ham who may not be in HT range of a digital repeater (DMR, DSTAR, YSF and others) to access them over the internet with his HT.  KE0FHS provided his experience with building and operating several types of digital hot spots. Toshen's review of several hot spot devices on the market may also be useful to the Ham thinking about implementing a digital hot spot. Toshen's article also contains several notes on where many useful devices for building Raspberry Pi based applications may be found.