SoftwareSerial2 is an advanced version of the SoftwareSerial library available as part of Arduino. It is based on Ladyada's AFSoftSerial library, to which it adds support for multiple input ports.

Please notice that the library currently does NOT support multiple input ports all at once. No library has yet been able to do so.

The following library does allow for multiple input ports but they need to be read one at a time: http://arduiniana.org/libraries/newsoftserial/