Serial: how to communicate in 9 bits?

I want to interface with a bit of hardware that uses an asynchronous serial interface with 8 data bits and 1 stop bit. Now, I read the Reference docs on Serial and SoftwareSerial, and these appear to send data only in byte-sized chunks.

What would be a good approach to send 9 bits using the digital 0 and 1 pins on a Duemilanove?

You already do send 8 data, one stop. The stop bit is automatically added by the AVR's UART or the software serial libraries.

No 8 data 1 stop is how it communicants. There is no conflict between your device and the serial port. There is even no need to use software serial.

Awesome. Thanks for your replies. Sometimes, life is easy ;)

send data only in byte-sized chunks

well byte is 8 bits ;) then there is the stop bit.

Don't confuse bites and bits :)