A belated postscript on this subject. I've finally found a relatively painless way of getting a set of MyInfo notes (read-only, of course) onto my iPhone with decent formatting. I mentioned a long time ago that I had tried using Stanza, the e-reader, but it stripped out italics and bold.
So here is the solution. I export a complete topic as a single RTF file. Then I open that file in OpenOffice and export it as as PDF file. Using the program Calibre, I convert the PDF into an ePub document. I then import the ePub document into the desktop version of Stanza, and Stanza on my iPhone recognizes the ePub file and downloads it to my Stanza library.
Sounds complicated, but it takes less than five minutes once you have all the software lined up. It might be possible to skip the conversion to PDF (in other words, go straight from RTF to ePub); I haven't experimented long enough with it to find out whether that's the case. The key is to do the conversion into ePub in Calibre rather than Stanza; that is what preserves the formatting.
Stanza produces extremely attractive typography, has a good search capability, and is a pleasure to use. At last I can transfer my notes from myInfo to my iPhone with a minimum of fuss.