High frequency audio sampling and storage
After doing some reading here Serial.begin(): Why not always use 28800? and looking at the manual for the 168. You should be able to achieve the baud rate you want by directly programming the USAR.

According to the answer there you should be able to use miniterm to keep up with a high baud rate.

As stated there you might run into problems with computer power. 

Read chapter 20 here http://www.atmel.com/images/doc2545.pdf.

Basically you can set up the USART speed (UDR0) and the control registers (UCSR0A,UCSR0B and UCSR0C) such that you can send data pretty fast. 

Let me know if you can't access that link and if you need me to explain some more about these things.