The Handspring VisorPhone Module plugs into the Springboard port on the Visor PDAs and turns it into a mobile phone. It allowed people to make calls and send SMS messages from their PDA, using the GSM network. It also has the ability to send and receive e-mail and to view Web content.

This VisorPhone module has OmniSky branding on it. OmniSky International was a partnership between US-based OmniSky Corporation and News International and who planned to launch its integrated wireless email and Web browsing service across Europe in 2001. In early 2001 OmniSky ran a beta trial using Handspring's Visor and VisorPhone GSM add-on in the UK. During this beta trial the voice channel was not enabled, to avoid complications. However, OmniSky failed to generate any revenue and was in trouble by the end of 2001. The plan to launch the service across Europe never appears to have materialised.

The SpringBoard Expansion Slot was a versatile expansion slot devised for Handspring's range of Palm OS PDAs. The interface inspired many creative products because it made it possible to use the PDA as a flexible interface to otherwise technically difficult to manage sophisticated hardware. Among the many available modules were auxiliary memory, game plug-ins, GPS navigation receivers, cameras, GSM and CDMA mobile phones, versatile infrared remote controls, wired and wireless network interface cards, Bluetooth modules, MP3 players, cordless phones with answering machines, and voice recorders.