Whilst the Garmin PNDs thrived the mobile side of the business struggled. This seems about to change as Garmin now have a mobile app running on the Apple iPhone/iPad platform that takes their PND application functionality into the SmartPhone arena.
Garmin have tried to enter the mobile market in a number of different ways with Android, Microsoft and Blackberry devices. The Android attempt was effectively an effort to produce a customised Android Phone based around Garmin Navigation as part of the early Android Alliance in conjunction with Asus. The Asus alliance also produced two Windows Mobile devices, but these initiatives were both late to market and never really caught on. The Blackberry attempt saw Garmin introduce off-board navigation. This trend is quite big in the USA, but it is carrier led and as far as I am aware no navigation company has been successful introducing off-board navigation in its own right. Whilst the application worked OK it really was not up to the normal Garmin standard (different User Interface) and was also hampered by the hardware. Although Blackberry has a large installed base the application was not compatible with the more popular Windows Mobile, Apple, Android or Nokia devices.
Last year Garmin once again tried to bring an off-board mapping solution to the SmartPhone market in the USA, and is now having some success with the iPhone application currently sitting at 11th in the Navigation category. However things are different in Europe! Having learnt the lesson that users do not like relying on a data connection for map data Garmin has now evolved it's StreetPilot software and produced an application with integral on-board mapping.