It is highly unlikely that you will find a USB MCU in a DIP package. There are a number of reasons for this as follows:

1) The world has moved beyond DIP packages.
2) DIP packages have limited pin counts in practical sizes and many parts now have many more pins.
3) Devices have transitioned away from 5V operation and lower voltage parts require the better power feed through the lead frame offered by smaller packages.
4) USB uses differential pair signalling and many times operates at a higher frequency. DIP packages are less than ideal for these characteristics.

You may be able to locate a suitable USB microcontroller that can be soldered to a DIP prototyping adapter. This does have the disadvantages of being fairly expensive and carries with it all the issues of DIP packages.

I have to guess that your desire for a DIP package is geared toward ease of prototyping. I have to suggest that you will be way better off purchasing a modular type solution that has the USB microcontroller mounted onto a small board along with its USB connector. Many vendors, such as SiLabs offer Evaluation boards that provide this type of functionality. (http://www.silabs.com/products/...40DK.aspx). Other vendors offer devices mounted on modules called breakout boards that are easy to adapt into prototypes. One vendor of breakout modules is SparkFun but their USB modules are generally not 8051 based parts. (http://www.sparkfun.com/products/762).

Michael Karas