Branko Collins' method is for my taste much to long & this is a crux: a manual method. I can be much better. Gutenmark
was discussed in this forum. It works great. Gutmarks does all conversion you want in an automated way. ;.)
gutenmark --latex in.txt out.tex
gutenmark in.txt out.html
[Edit]: There are versions of gutenmark for Windows, Mac, & Linux.