From Giltesa, a spanish blog about electronics, we have found a very interesting tutorial for 433MHz RF Modules.
One of the projects showed in the blog is to build a weather station so it is needed to know both outdoor and indoor temperature. To connect the sensors to Arduino wirelessly. 433 MHz RF modules allow to connect two Arduinos in order to communicate them unidirectionally. The Arduino in outdoor will send the signal to the other one which will show the data in the screen. Transmitter works with a voltage between 3 and 12V and the receiver works at 5V.
Get the codes for each module here.
Via and Source: Giltesa.