NSLU2 Linux wiki has an extensive list of options for 3.3V to RS232 or
USB conversion:
Also, check out FOX console board using just a couple of transistors and
diods: http://www.acmesystems.it/?id=106
Sergey, would this work with PCs? I thought RS232 needed negative and positive voltage swings. Unless the lines are AC-coupled on the PC, I'm surprised that this would work.
Nice finds already there regarding TTL-to-RS232 conversions. No need to spend >$20.