You want to make this thing talk to that thing waaay over there? Try the SeeedStudio super-long range 433Mhz RF link bundle! They're claiming 2KM range for wireless data transport & remote control use!
This 315MHz RF transmitter/receiver set is a simple 100M remote-operation control link
Bluetooth! XBee! Arrgh - which way to go? Well, the Bluetooth Bee lets you jam a Bluetooth SPP module into an existing Xbee socket ed project!
It's Laser time boys (and girls)! The long awaited Laser Range finder from the Joe Grand/Parallax team-up is here! This sensor is able find objects and walls with ultimate precision and makes laser ranging technology finally affordable.
Better than XBee at a comparable cost! This module features the powerful ATmega128RFA1, transmitting on 2.4GHz with OTA (Over-The-Air) speeds up to 2Mbps, maximum 4.8km (3 miles) range and an SMA antenna connector for optimum performance.
This ATTiny24-based 433MHz platform is a remote sensor base. Add up to 4 sensors (analog or digital), and configure the board's broadcast schedule!