Hi Chaitanya,
On 26th October 2005, I was in Pune attending a seminar from Silicon Labs.
They had demonstrated a chip 2101, I don't remember the exact name prefixes of this chip. This chip is a convertor from Serial Port to USB and the other way round. This chip is costing about Rs.200/-, No MOQ (Minumum Order Quantity) requirements you can purchase even a single IC. These are available at hynetic, they are having an office in Pune. I am sure some of the Pune engineers on this forum might be able to help in getting their contact details. They have Demo board (they call it SDK) for it, the cost on the day of the seminar was about Rs.2500/-(discounted price). With this SDK, they give you the Windows Driver free of charge, they also give you the circuit diagram and a sample board. the beauty of this chip is that you just have to solder this chip and you product is USB enabled. Go through the data sheets of this device. Be sure to study its package type, because it is surely going to be very challenging when soldering this chip.

Bye,

From Mr. Kiran V. Sutar.