The least painful way I know of inserting a Greek letter in a text is to use the math mode and the corresponding command. This will produce an alpha letter :
$\alpha$
But this always produces an italic letter. I never thought about it until now, but when should this letter be italic, and when should it not?
Furthermore, if I am talking about microseconds in my text, there will be one Latin and one Greek letter side by side. Which of the following should I use?
1- The average time of this event is 50 $\mu s$.
2- The average time of this event is 50 $\mu$s.
3- The average time of this event is 50 $\mathrm{\mu s}.
4- The average time of this event is 50 μs.
Now to me it's either #1 or #3, as #2 produces one italic letter and one normal letter (that's kind of a visual clash), and #4 is only usable if your document is encoded using UTF-X. What do you do when facing this?

