Can an Arduino Nano be used as a serial programmer?

I have a project where I need to interface to a serial device through the USB. Can I use a Nano for this purpose since I already have a bunch of them?

I did some research, and it seems on Uno you have to pull the 328 chip, on Nano reset has to be pulled high? Didn't find anything definitive. ::)

Is this possible?

You can tie reset to ground (forcing chip to stay in reset), and then use it as just a serial adapter.

You cannot use it to program an arduino over serial, though, without modifying the board, because you need the DTR pin, which isn't broken out on the nano, for that.

USB serial adapters are like $5 or less, I suggest investing in proper ones with the 6-pin programming header.

Thanks, I just need to communicate with another serial device through RX/TX only.

Should RST be tied to GND through a resistor?

No, without resistor.