I tend to use a lot of ellipses and double-dashes in my purple prose, and I hate it when they wrap to the beginning of a line. The <nobr> tag doesn't seem to work in WordPress, so I've learned to use to hold the punctuation to the previous word:
In other words
...
This works fine, but i have noticed than when I go in to re-edit the post, I have to re-enter the codes, or they convert to standard spaces and the punctuation wraps.
I guess I should add that I use the Regulus theme, but I don't know if this is a Regulus problem or a WordPress problem.