Internet GIS provides a collaborative communication environment for sharing data, information, and knowledge. Mobile GIS can add both geospatial information and global positional systems (GPS) coordinates from remotely located field-based personnel to spatial decision support systems (SDSS). By adopting broadband wireless telecommunication technology for connecting Internet GIS and mobile GIS devices, decision makers can gather near real-time information from field personnel and, equally quickly, distribute updated information back to the field. This chapter introduces a collaborative GIS prototype that demonstrates an interoperable framework for combining Web-based GIS technologies and wireless mobile GIS applications. The integrated framework provides real-time or near real-time GIS data update functions (such as adding new spatially located map features or GPS tracking locations) between mobile GIS devices and Internet GIS servers. Although these real-time GIS functions can be very important during time-urgent emergencies, they can be equally beneficial and highly cost effective during routine field activities.